build: follow the rename through config, packaging and docs

  config/config.kdl   plugin path -> ~/.config/sl0ppij/plugins, builtin plugins
                      -> the sl0ppij: URL scheme. Verified to load under the
                      renamed binary ("[CONFIG FILE]: Well defined.").
  install-config.sh   syncs to ~/.config/sl0ppij
  install.sh          a stock zellij on the target is no longer a warning, it is
                      just a fact: the two coexist
  stage.sh            drops the "renaming at package time is a fig leaf" note
  Makefile            builds `-p zellij` (package) and ships `sl0ppij` (binary);
                      `make check` now also gates the root package, using the
                      prebuilt asset plugins so it does not need debug wasm
  docs/               rename.md records what was done, what was deliberately
                      left (plugin-internal strings live in prebuilt wasm), and
                      the verification actually performed

1 files changed, 5 insertions, 3 deletions

diff --git a/.gitignore b/.gitignore
index 8201aef..0c5dd6d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,6 +1,8 @@
-# build artifacts
-/target/
-**/target/
+# build artifacts (dir, or a symlink to a shared cache on a cramped dev box --
+# the debug-plugin include! path resolves relative to the source tree, so
+# CARGO_TARGET_DIR alone is not enough)
+/target
+**/target
 /dist/
 /build/