docs: what dogfooding asked of the second round

The served README, the skill and docs/fs.md now say where an address search
starts, that an event record's text may hold newlines and is read by its
count, that truncating tag clears its default words too (append to keep them,
u in the tag to get them back), how Dump and Restore behave and where dumps
go, that Kill stops only the foreground job (the rest of 'sleep 30; echo done'
still runs) and that Joincol needs a column to the right. The skill and
fs.md had Collapse as a column word; it folds the pane it is given.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 20 insertions, 10 deletions

diff --git a/docs/fs.md b/docs/fs.md
index 41b960f2..ae5e27ad 100644
--- a/docs/fs.md
+++ b/docs/fs.md
@@ -127,17 +127,21 @@ to its end mark (D); Kill sends its foreground job SIGTERM -- acme posts the
 "kill" note, which ends a process -- and never signals the shell itself;
 in a shell running without job control (`set +m`) the job shares the
 shell's group, so there is none to signal: Kill says `Kill: no job to
-signal`, and a write of it to `ctl` fails with that --
+signal`, and a write of it to `ctl` fails with that; and only the
+foreground job, so of `sleep 30; echo done` the `echo` still runs once the
+`sleep` is stopped --
 and reads every setting there is, one a line, in the words a write of it
 takes (`Verbose on`, `WindowOpacity 70`, `PanelSlide off`, `DumpDir` bare
 for the default directory, `LocationsConfig ...`), so writing what it reads
 back changes nothing; platform and startup facts are `/status`'s and the
 Config window's, not settings. A pane's `ctl` takes the builtins that act on
-a pane (`Del`, `Save f`, `Collapse`, `Find pat`) beside acme's `get`, `lock`
-and `unlock`. The column words are pane words too, acting on the column that
-pane is in: `Delcol`, `Collapse`, `DelAbove`, `DelBelow` and the focus moves
-`Left`/`Right`/`Up`/`Down` from it. `Joincol` and `Newcol` are the root's:
-they act on the column of the pane with the keyboard. The words are case-sensitive and do not alias: acme's verbs
+a pane (`Del`, `Save f`, `Collapse`, which folds that pane, `Find pat`)
+beside acme's `get`, `lock` and `unlock`. The column words are pane words
+too, acting on the column that pane is in: `Delcol`, `DelAbove`, `DelBelow`
+and the focus moves `Left`/`Right`/`Up`/`Down` from it. `Joincol` and
+`Newcol` are the root's: they act on the column of the pane with the
+keyboard, and `Joincol` needs a column to its right (`Joincol: no column to
+the right`). The words are case-sensitive and do not alias: acme's verbs
 are lowercase and the builtins keep their tag spelling, so `Get` is no word
 and `del` none either.
 
@@ -344,9 +348,12 @@ pane.
 `tag` reads the whole tag as the pane shows it: the computed path, dirty
 marker or PDF page, then the text you may edit. A write appends to that text,
 newlines included, and a tag with more than one line takes a row per line on
-screen; truncating `tag` clears it, as acme's `cleartag` does. The clearing
-is an edit of the tag like a typed one and its undo history is kept: `u` in
-the tag brings back the text it cleared.
+screen; truncating `tag` clears it, as acme's `cleartag` does -- the default
+words (`Del`, `Put` and the rest) with it, since they are that text until
+you edit it, so `echo Make > tag` leaves only `Make`; append with `>>` to
+keep them. The clearing is an edit of the tag like a typed one and its undo
+history is kept: `u` in the tag brings back the text it cleared, words
+included.
 
 Stats report real lengths for `index`, `status`, `look`, `exec`, `listeners`,
 `name`, `body`, `tag`, `sel`, `ctl`, the range files and the flag files, and
@@ -385,7 +392,10 @@ acme's `errors` only takes text, and one record stream is simpler to watch
 than a file per pane. A `msg` said while a
 pane is being made can precede that pane's `new`; panes present at boot are
 recorded before anything else.
-Control characters in a record become spaces, so a record is one line. An
+Control characters in a record become spaces, so a record is one line.
+(An `event` record is not: acme's `<origin><action><q0> <q1> <flag> <n>
+<text>\n`, whose text may hold newlines; read `n` bytes of it rather than
+up to a newline -- bytes here, where acme counts runes.) An
 open freezes the ring's text the way `/screen` freezes a frame: reads walk it
 and end. Writing `follow` to that same open makes reads past it wait for the
 next record, one per read; a follower the ring outran reads `lost N` first.