docs: the tab bar's new shapes, written down

A 'The tab bar' section on the panes page: the sidebar, its four knobs,
the status rows under each tab, and the borrowed directory name for
unnamed tabs. The config page's knob table learns the tab_bar_* keys.

scripting.md and the driving-slosh skill stop underselling the status
verb: it was documented back when the pane's own frame was the only
place a status could appear, which made it decoration. With the
sidebar it is how a pane reports progress to somebody working in
another tab -- so say that, and say to keep it current and clear it
when the work is done.

1 files changed, 6 insertions, 0 deletions

diff --git a/docs/scripting.md b/docs/scripting.md
index 5ae448f..941dd7f 100644
--- a/docs/scripting.md
+++ b/docs/scripting.md
@@ -101,6 +101,12 @@ The status text appears in the pane's frame; the buttons are real targets in it.
 A program that wants to be asked something can ask *in place* rather than
 printing a prompt and hoping.
 
+With the tab bar [on a side](panes.md#the-tab-bar), the status is also a row
+under the pane's tab — visible from every other tab, and clicking it jumps to
+the pane that said it. A status is not decoration on your own frame; it is how
+a pane reports progress to somebody working elsewhere, which is a reason to
+keep it current and `clear` it when the work is done.
+
 `purpose` is the other verb: `printf '\033]5577;1;purpose;logs\033\\'`. A purpose
 declared by a layout or the control API wins and cannot be overwritten this way.