Add `template` section in `layout` file

It works as follows:
```
---
template:
  direction: Horizontal
  parts:
    - direction: Vertical
      split_size:
        Fixed: 1
      run:
        plugin: tab-bar
    - direction: Vertical
      body: true
    - direction: Vertical
      split_size:
        Fixed: 2
      run:
        plugin: status-bar
tabs:
  - direction: Vertical
```

The tabs are created in the body section of the template.

8 files changed, 244 insertions, 268 deletions

diff --git a/zellij-utils/src/input/unit/fixtures/layouts/deeply-nested-tab-layout.yaml b/zellij-utils/src/input/unit/fixtures/layouts/deeply-nested-tab-layout.yaml
index 11e5323e..633a1fae 100644
--- a/zellij-utils/src/input/unit/fixtures/layouts/deeply-nested-tab-layout.yaml
+++ b/zellij-utils/src/input/unit/fixtures/layouts/deeply-nested-tab-layout.yaml
@@ -1,40 +1,43 @@
 ---
-direction: Horizontal
-parts:
-  - direction: Vertical
-    parts:
-      - direction: Horizontal
-        split_size:
-          Percent: 21
-      - direction: Vertical
-        split_size:
-          Percent: 79
-        parts:
-          - direction: Horizontal
-            split_size:
-              Percent: 22
-          - direction: Horizontal
-            split_size:
-              Percent: 78
-            parts:
-              - direction: Horizontal
-                split_size:
-                  Percent: 23
-              - direction: Vertical
-                split_size:
-                  Percent: 77
-                tabs:
-                  - direction: Horizontal
-                    split_size:
-                      Percent: 24
+template:
+  direction: Horizontal
+  parts:
+    - direction: Vertical
+      parts:
+        - direction: Horizontal
+          split_size:
+            Percent: 21
+        - direction: Vertical
+          split_size:
+            Percent: 79
+          parts:
+            - direction: Horizontal
+              split_size:
+                Percent: 22
+            - direction: Horizontal
+              split_size:
+                Percent: 78
+              parts:
+                - direction: Horizontal
+                  split_size:
+                    Percent: 23
+                - direction: Vertical
+                  split_size:
+                    Percent: 77
+                  body: true
+      split_size:
+        Percent: 90
+    - direction: Vertical
+      split_size:
+        Percent: 15
+    - direction: Vertical
+      split_size:
+        Percent: 15
+    - direction: Vertical
+      split_size:
+        Percent: 15
+
+tabs:
+  - direction: Horizontal
     split_size:
-      Percent: 90
-  - direction: Vertical
-    split_size:
-      Percent: 15
-  - direction: Vertical
-    split_size:
-      Percent: 15
-  - direction: Vertical
-    split_size:
-      Percent: 15
+      Percent: 24
diff --git a/zellij-utils/src/input/unit/fixtures/layouts/no-tabs-should-error.yaml b/zellij-utils/src/input/unit/fixtures/layouts/no-tabs-should-error.yaml
deleted file mode 100644
index a67b0ff9..00000000
--- a/zellij-utils/src/input/unit/fixtures/layouts/no-tabs-should-error.yaml
+++ /dev/null
@@ -1,18 +0,0 @@
----
-direction: Horizontal
-parts:
-  - direction: Horizontal
-    parts:
-      - direction: Vertical
-        parts:
-          - direction: Horizontal
-            split_size:
-              Percent: 50
-          - direction: Horizontal
-            parts:
-              - direction: Vertical
-                split_size:
-                  Percent: 50
-              - direction: Vertical
-                split_size:
-                  Percent: 50
diff --git a/zellij-utils/src/input/unit/fixtures/layouts/tabs-and-parts-together-should-error.yaml b/zellij-utils/src/input/unit/fixtures/layouts/tabs-and-parts-together-should-error.yaml
deleted file mode 100644
index e7223602..00000000
--- a/zellij-utils/src/input/unit/fixtures/layouts/tabs-and-parts-together-should-error.yaml
+++ /dev/null
@@ -1,17 +0,0 @@
----
-direction: Horizontal
-parts:
-  - direction: Horizontal
-    tabs:
-      - direction: Vertical
-        parts:
-          - direction: Horizontal
-            split_size:
-              Percent: 50
-    parts:
-      - direction: Vertical
-        split_size:
-          Percent: 50
-      - direction: Vertical
-        split_size:
-          Percent: 50
diff --git a/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab-and-command.yaml b/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab-and-command.yaml
index 34de4291..9ad1034d 100644
--- a/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab-and-command.yaml
+++ b/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab-and-command.yaml
@@ -1,32 +1,35 @@
 ---
-direction: Horizontal
-parts:
+template:
+  direction: Horizontal
+  parts:
+    - direction: Vertical
+      split_size:
+        Fixed: 1
+      run:
+        plugin: tab-bar
+    - direction: Horizontal
+      body: true
+    - direction: Vertical
+      split_size:
+        Fixed: 2
+      run:
+        plugin: status-bar
+
+tabs:
   - direction: Vertical
-    split_size:
-      Fixed: 1
-    run:
-      plugin: tab-bar
-  - direction: Horizontal
-    tabs:
-      - direction: Vertical
+    parts:
+      - direction: Horizontal
+        split_size:
+          Percent: 50
+      - direction: Horizontal
         parts:
-          - direction: Horizontal
+          - direction: Vertical
             split_size:
               Percent: 50
-          - direction: Horizontal
-            parts:
-              - direction: Vertical
-                split_size:
-                  Percent: 50
-                run:
-                  command: {cmd: htop}
-              - direction: Vertical
-                split_size:
-                  Percent: 50
-                run:
-                  command: {cmd: htop, args: ["-C"]}
-  - direction: Vertical
-    split_size:
-      Fixed: 2
-    run:
-      plugin: status-bar
+            run:
+              command: {cmd: htop}
+          - direction: Vertical
+            split_size:
+              Percent: 50
+            run:
+              command: {cmd: htop, args: ["-C"]}
diff --git a/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab-and-default-plugins.yaml b/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab-and-default-plugins.yaml
index a803f291..88046395 100644
--- a/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab-and-default-plugins.yaml
+++ b/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab-and-default-plugins.yaml
@@ -1,28 +1,31 @@
 ---
-direction: Horizontal
-parts:
+template:
+  direction: Horizontal
+  parts:
+    - direction: Vertical
+      split_size:
+        Fixed: 1
+      run:
+        plugin: tab-bar
+    - direction: Horizontal
+      body: true
+    - direction: Vertical
+      split_size:
+        Fixed: 2
+      run:
+        plugin: status-bar
+
+tabs:
   - direction: Vertical
-    split_size:
-      Fixed: 1
-    run:
-      plugin: tab-bar
-  - direction: Horizontal
-    tabs:
-      - direction: Vertical
+    parts:
+      - direction: Horizontal
+        split_size:
+          Percent: 50
+      - direction: Horizontal
         parts:
-          - direction: Horizontal
+          - direction: Vertical
+            split_size:
+              Percent: 50
+          - direction: Vertical
             split_size:
               Percent: 50
-          - direction: Horizontal
-            parts:
-              - direction: Vertical
-                split_size:
-                  Percent: 50
-              - direction: Vertical
-                split_size:
-                  Percent: 50
-  - direction: Vertical
-    split_size:
-      Fixed: 2
-    run:
-      plugin: status-bar
diff --git a/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab.yaml b/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab.yaml
index e0f25b92..83f05076 100644
--- a/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab.yaml
+++ b/zellij-utils/src/input/unit/fixtures/layouts/three-panes-with-tab.yaml
@@ -1,18 +1,21 @@
 ---
-direction: Horizontal
-parts:
-  - direction: Horizontal
-    tabs:
-      - direction: Vertical
+template:
+  direction: Horizontal
+  parts:
+    - direction: Horizontal
+      body: true
+
+tabs:
+  - direction: Vertical
+    parts:
+      - direction: Horizontal
+        split_size:
+          Percent: 50
+      - direction: Horizontal
         parts:
-          - direction: Horizontal
+          - direction: Vertical
+            split_size:
+              Percent: 50
+          - direction: Vertical
             split_size:
               Percent: 50
-          - direction: Horizontal
-            parts:
-              - direction: Vertical
-                split_size:
-                  Percent: 50
-              - direction: Vertical
-                split_size:
-                  Percent: 50
diff --git a/zellij-utils/src/input/unit/fixtures/layouts/three-tabs-merged-correctly.yaml b/zellij-utils/src/input/unit/fixtures/layouts/three-tabs-merged-correctly.yaml
index 96e1524d..e2a09a73 100644
--- a/zellij-utils/src/input/unit/fixtures/layouts/three-tabs-merged-correctly.yaml
+++ b/zellij-utils/src/input/unit/fixtures/layouts/three-tabs-merged-correctly.yaml
@@ -1,25 +1,29 @@
 ---
-direction: Vertical
-parts:
+template:
+  direction: Vertical
+  parts:
+    - direction: Horizontal
+      body: true
+    - direction: Horizontal
+
+
+tabs:
   - direction: Horizontal
-    tabs:
+    split_size:
+      Percent: 50
+  - direction: Horizontal
+    split_size:
+      Percent: 50
+    parts:
       - direction: Horizontal
         split_size:
           Percent: 50
       - direction: Horizontal
-        split_size:
-          Percent: 50
-        parts:
-          - direction: Horizontal
-            split_size:
-              Percent: 50
-          - direction: Horizontal
+  - direction: Vertical
+    split_size:
+      Percent: 50
+    parts:
       - direction: Vertical
         split_size:
           Percent: 50
-        parts:
-          - direction: Vertical
-            split_size:
-              Percent: 50
-          - direction: Horizontal
-  - direction: Horizontal
+      - direction: Horizontal
diff --git a/zellij-utils/src/input/unit/layout_test.rs b/zellij-utils/src/input/unit/layout_test.rs
index 1a90c1ff..d09d328c 100644
--- a/zellij-utils/src/input/unit/layout_test.rs
+++ b/zellij-utils/src/input/unit/layout_test.rs
@@ -15,40 +15,43 @@ fn default_layout_dir(layout: String) -> PathBuf {
 #[test]
 fn default_layout_is_ok() {
     let path = default_layout_dir("default.yaml".into());
-    let layout = Layout::new(&path);
+    let layout = LayoutFromYaml::new(&path);
     assert!(layout.is_ok());
 }
 
 #[test]
 fn default_layout_has_one_tab() {
     let path = default_layout_dir("default.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    assert_eq!(main_layout.tabs.len(), 1);
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap().construct_layout_template();
+    assert_eq!(layout_template.tabs.len(), 1);
 }
 
 #[test]
 fn default_layout_has_one_pre_tab() {
     let path = default_layout_dir("default.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    assert_eq!(main_layout.pre_tab.parts.len(), 1);
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap().construct_layout_template();
+    assert_eq!(layout_template.pre_tab.parts.len(), 1);
 }
 
 #[test]
 fn default_layout_has_one_post_tab() {
     let path = default_layout_dir("default.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    assert_eq!(main_layout.post_tab.len(), 1);
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap().construct_layout_template();
+    assert_eq!(layout_template.post_tab.len(), 1);
 }
 
 #[test]
 fn default_layout_merged_correctly() {
     let path = default_layout_dir("default.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    let tab_layout = main_layout.construct_tab_layout(Some(main_layout.tabs[0].clone()));
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml
+        .as_ref()
+        .unwrap()
+        .construct_layout_template();
+    let tab_layout = layout_template.construct_tab_layout(Some(layout_template.tabs[0].clone()));
     let merged_layout = Layout {
         direction: Direction::Horizontal,
         parts: vec![
@@ -84,9 +87,12 @@ fn default_layout_merged_correctly() {
 #[test]
 fn default_layout_new_tab_correct() {
     let path = default_layout_dir("default.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    let tab_layout = main_layout.construct_tab_layout(None);
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml
+        .as_ref()
+        .unwrap()
+        .construct_layout_template();
+    let tab_layout = layout_template.construct_tab_layout(None);
     let merged_layout = Layout {
         direction: Direction::Horizontal,
         parts: vec![
@@ -122,78 +128,84 @@ fn default_layout_new_tab_correct() {
 #[test]
 fn default_strider_layout_is_ok() {
     let path = default_layout_dir("strider.yaml".into());
-    let layout = Layout::new(&path);
-    assert!(layout.is_ok());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    assert!(layout_from_yaml.is_ok());
 }
 
 #[test]
 fn default_disable_status_layout_is_ok() {
     let path = default_layout_dir("disable-status-bar.yaml".into());
-    let layout = Layout::new(&path);
-    assert!(layout.is_ok());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    assert!(layout_from_yaml.is_ok());
 }
 
 #[test]
-fn default_disable_status_layout_has_one_tab() {
+fn default_disable_status_layout_has_no_tab() {
     let path = default_layout_dir("disable-status-bar.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    assert_eq!(main_layout.tabs.len(), 1);
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml
+        .as_ref()
+        .unwrap()
+        .construct_layout_template();
+    assert_eq!(layout_template.tabs.len(), 0);
 }
 
 #[test]
 fn default_disable_status_layout_has_one_pre_tab() {
     let path = default_layout_dir("disable-status-bar.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    assert_eq!(main_layout.pre_tab.parts.len(), 1);
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml
+        .as_ref()
+        .unwrap()
+        .construct_layout_template();
+    assert_eq!(layout_template.pre_tab.parts.len(), 1);
 }
 
 #[test]
 fn default_disable_status_layout_has_no_post_tab() {
     let path = default_layout_dir("disable-status-bar.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    assert!(main_layout.post_tab.is_empty());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap().construct_layout_template();
+    assert!(layout_template.post_tab.is_empty());
 }
 
 #[test]
 fn three_panes_with_tab_is_ok() {
     let path = layout_test_dir("three-panes-with-tab.yaml".into());
-    let layout = Layout::new(&path);
+    let layout = LayoutFromYaml::new(&path);
     assert!(layout.is_ok());
 }
 
 #[test]
 fn three_panes_with_tab_has_one_tab() {
     let path = layout_test_dir("three-panes-with-tab.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.unwrap().construct_main_layout().unwrap();
-    assert_eq!(main_layout.tabs.len(), 1);
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.unwrap().construct_layout_template();
+    assert_eq!(layout_template.tabs.len(), 1);
 }
 
 #[test]
 fn three_panes_with_tab_no_post_tab() {
     let path = layout_test_dir("three-panes-with-tab.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.unwrap().construct_main_layout().unwrap();
-    assert!(main_layout.post_tab.is_empty());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.unwrap().construct_layout_template();
+    assert!(layout_template.post_tab.is_empty());
 }
 
 #[test]
 fn three_panes_with_tab_no_pre_tab() {
     let path = layout_test_dir("three-panes-with-tab.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.unwrap().construct_main_layout().unwrap();
-    assert!(main_layout.pre_tab.parts.is_empty());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.unwrap().construct_layout_template();
+    assert!(layout_template.pre_tab.parts.is_empty());
 }
 
 #[test]
 fn three_panes_with_tab_merged_correctly() {
     let path = layout_test_dir("three-panes-with-tab.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    let tab_layout = main_layout.construct_tab_layout(Some(main_layout.tabs[0].clone()));
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap().construct_layout_template();
+    let tab_layout = layout_template.construct_tab_layout(Some(layout_template.tabs[0].clone()));
     let merged_layout = Layout {
         direction: Direction::Horizontal,
         parts: vec![Layout {
@@ -243,9 +255,9 @@ fn three_panes_with_tab_merged_correctly() {
 #[test]
 fn three_panes_with_tab_new_tab_is_correct() {
     let path = layout_test_dir("three-panes-with-tab.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    let tab_layout = main_layout.construct_tab_layout(None);
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap().construct_layout_template();
+    let tab_layout = layout_template.construct_tab_layout(None);
     let merged_layout = Layout {
         direction: Direction::Horizontal,
         parts: vec![Layout {
@@ -265,40 +277,40 @@ fn three_panes_with_tab_new_tab_is_correct() {
 #[test]
 fn three_panes_with_tab_and_default_plugins_is_ok() {
     let path = layout_test_dir("three-panes-with-tab-and-default-plugins.yaml".into());
-    let layout = Layout::new(&path);
+    let layout = LayoutFromYaml::new(&path);
     assert!(layout.is_ok());
 }
 
 #[test]
 fn three_panes_with_tab_and_default_plugins_has_one_tab() {
     let path = layout_test_dir("three-panes-with-tab-and-default-plugins.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.unwrap().construct_main_layout().unwrap();
-    assert_eq!(main_layout.tabs.len(), 1);
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.unwrap().construct_layout_template();
+    assert_eq!(layout_template.tabs.len(), 1);
 }
 
 #[test]
 fn three_panes_with_tab_and_default_plugins_one_post_tab() {
     let path = layout_test_dir("three-panes-with-tab-and-default-plugins.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.unwrap().construct_main_layout().unwrap();
-    assert_eq!(main_layout.post_tab.len(), 1);
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.unwrap().construct_layout_template();
+    assert_eq!(layout_template.post_tab.len(), 1);
 }
 
 #[test]
 fn three_panes_with_tab_and_default_plugins_has_pre_tab() {
     let path = layout_test_dir("three-panes-with-tab-and-default-plugins.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.unwrap().construct_main_layout().unwrap();
-    assert!(!main_layout.pre_tab.parts.is_empty());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.unwrap().construct_layout_template();
+    assert!(!layout_template.pre_tab.parts.is_empty());
 }
 
 #[test]
 fn three_panes_with_tab_and_default_plugins_merged_correctly() {
     let path = layout_test_dir("three-panes-with-tab-and-default-plugins.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    let tab_layout = main_layout.construct_tab_layout(Some(main_layout.tabs[0].clone()));
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap().construct_layout_template();
+    let tab_layout = layout_template.construct_tab_layout(Some(layout_template.tabs[0].clone()));
     let merged_layout = Layout {
         direction: Direction::Horizontal,
         parts: vec![
@@ -364,9 +376,9 @@ fn three_panes_with_tab_and_default_plugins_merged_correctly() {
 #[test]
 fn three_panes_with_tab_and_default_plugins_new_tab_is_correct() {
     let path = layout_test_dir("three-panes-with-tab-and-default-plugins.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    let tab_layout = main_layout.construct_tab_layout(None);
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap().construct_layout_template();
+    let tab_layout = layout_template.construct_tab_layout(None);
     let merged_layout = Layout {
         direction: Direction::Horizontal,
         parts: vec![
@@ -402,40 +414,40 @@ fn three_panes_with_tab_and_default_plugins_new_tab_is_correct() {
 #[test]
 fn deeply_nested_tab_is_ok() {
     let path = layout_test_dir("deeply-nested-tab-layout.yaml".into());
-    let layout = Layout::new(&path);
+    let layout = LayoutFromYaml::new(&path);
     assert!(layout.is_ok());
 }
 
 #[test]
 fn deeply_nested_tab_has_one_tab() {
     let path = layout_test_dir("deeply-nested-tab-layout.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.unwrap().construct_main_layout().unwrap();
-    assert_eq!(main_layout.tabs.len(), 1);
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.unwrap().construct_layout_template();
+    assert_eq!(layout_template.tabs.len(), 1);
 }
 
 #[test]
 fn deeply_nested_tab_three_post_tab() {
     let path = layout_test_dir("deeply-nested-tab-layout.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.unwrap().construct_main_layout().unwrap();
-    assert_eq!(main_layout.post_tab.len(), 3);
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.unwrap().construct_layout_template();
+    assert_eq!(layout_template.post_tab.len(), 3);
 }
 
 #[test]
 fn deeply_nested_tab_has_many_pre_tab() {
     let path = layout_test_dir("deeply-nested-tab-layout.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.unwrap().construct_main_layout().unwrap();
-    assert!(!main_layout.pre_tab.parts.is_empty());
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.unwrap().construct_layout_template();
+    assert!(!layout_template.pre_tab.parts.is_empty());
 }
 
 #[test]
 fn deeply_nested_tab_merged_correctly() {
     let path = layout_test_dir("deeply-nested-tab-layout.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    let tab_layout = main_layout.construct_tab_layout(Some(main_layout.tabs[0].clone()));
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap().construct_layout_template();
+    let tab_layout = layout_template.construct_tab_layout(Some(layout_template.tabs[0].clone()));
     let merged_layout = Layout {
         direction: Direction::Horizontal,
         parts: vec![
@@ -519,57 +531,37 @@ fn deeply_nested_tab_merged_correctly() {
 }
 
 #[test]
-fn no_tabs_specified_should_err() {
-    let path = layout_test_dir("no-tabs-should-error.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.unwrap().construct_main_layout();
-    assert!(main_layout.is_err());
-}
-
-#[test]
-fn tabs_and_parts_specified_together_should_should_err() {
-    let path = layout_test_dir("tabs-and-parts-together-should-error.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.unwrap().construct_main_layout();
-    assert!(main_layout.is_err());
-}
-
-#[test]
-fn multiple_tabs_specified_should_not_err() {
-    let path = layout_test_dir("multiple-tabs-should-not-error.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.unwrap().construct_main_layout();
-    assert!(main_layout.is_ok())
-}
-#[test]
 fn three_tabs_is_ok() {
     let path = layout_test_dir("three-tabs-merged-correctly.yaml".into());
-    let layout = Layout::new(&path);
-    assert!(layout.is_ok());
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    assert!(layout_from_yaml.is_ok());
 }
 
 #[test]
 fn three_tabs_has_three_tabs() {
     let path = layout_test_dir("three-tabs-merged-correctly.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.unwrap().construct_main_layout().unwrap();
-    assert_eq!(main_layout.tabs.len(), 3);
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml.unwrap().construct_layout_template();
+    assert_eq!(layout_template.tabs.len(), 3);
 }
 
 #[test]
 fn three_tabs_has_one_post_tab() {
     let path = layout_test_dir("three-tabs-merged-correctly.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.unwrap().construct_main_layout().unwrap();
-    assert_eq!(main_layout.post_tab.len(), 1);
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml.unwrap().construct_layout_template();
+    assert_eq!(layout_template.post_tab.len(), 1);
 }
 
 #[test]
 fn three_tabs_tab_one_merged_correctly() {
     let path = layout_test_dir("three-tabs-merged-correctly.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    let tab_layout = main_layout.construct_tab_layout(Some(main_layout.tabs[0].clone()));
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml
+        .as_ref()
+        .unwrap()
+        .construct_layout_template();
+    let tab_layout = layout_template.construct_tab_layout(Some(layout_template.tabs[0].clone()));
     let merged_layout = Layout {
         direction: Direction::Vertical,
         parts: vec![
@@ -599,9 +591,12 @@ fn three_tabs_tab_one_merged_correctly() {
 #[test]
 fn three_tabs_tab_two_merged_correctly() {
     let path = layout_test_dir("three-tabs-merged-correctly.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    let tab_layout = main_layout.construct_tab_layout(Some(main_layout.tabs[1].clone()));
+    let layout_from_yaml = LayoutFromYaml::new(&path);
+    let layout_template = layout_from_yaml
+        .as_ref()
+        .unwrap()
+        .construct_layout_template();
+    let tab_layout = layout_template.construct_tab_layout(Some(layout_template.tabs[1].clone()));
     let merged_layout = Layout {
         direction: Direction::Vertical,
         parts: vec![
@@ -646,9 +641,9 @@ fn three_tabs_tab_two_merged_correctly() {
 #[test]
 fn three_tabs_tab_three_merged_correctly() {
     let path = layout_test_dir("three-tabs-merged-correctly.yaml".into());
-    let layout = Layout::new(&path);
-    let main_layout = layout.as_ref().unwrap().construct_main_layout().unwrap();
-    let tab_layout = main_layout.construct_tab_layout(Some(main_layout.tabs[2].clone()));
+    let layout = LayoutFromYaml::new(&path);
+    let layout_template = layout.as_ref().unwrap().construct_layout_template();
+    let tab_layout = layout_template.construct_tab_layout(Some(layout_template.tabs[2].clone()));
     let merged_layout = Layout {
         direction: Direction::Vertical,
         parts: vec![