fs.md and the 9P skill say what the language server words do over 9P

Hover, Rename, Diagnostics, Symbols, Lspinfo and Lspwhy work through exec
like any builtin, but neither fs.md nor the SKILL named them. So a script
did not know they act at the cursor (set with addr and dot=addr), where
their answers land (+Hover, +Search, +Lsp), that the write waits for the
answer, or that Lspwhy explains the last query. Each now says so briefly,
the SKILL with a short example.

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

1 files changed, 7 insertions, 0 deletions

diff --git a/docs/fs.md b/docs/fs.md
index 3e304b00..6a82b633 100644
--- a/docs/fs.md
+++ b/docs/fs.md
@@ -213,6 +213,13 @@ A line written to `exec` is a middle click:
   A builtin that needs its argument (`Msg`, `Mount`, `Find`) written bare is
   `wrong #args in control message "Msg"`, and so is one that takes none
   written with one (`Config extra`).
+- the language server's words ask about a file pane's text at its cursor
+  (set it with `addr` and `dot=addr` first): `Hover` fills `+Hover`,
+  `Rename new` renames the symbol everywhere and lists the places,
+  `Diagnostics` and `Symbols` list the file's in `+Search`, `Lspinfo` says
+  which server serves the file and its state, and `Lspwhy` narrates the
+  last query step by step (in `+Lsp`), to tell why it found nothing. The
+  write returns once the answer is in; a pane with no file is refused.
 - acme's words run as pardes's where it has one (`Put` is `Save`, `Delete`
   a `Del` that does not ask); the rest (`Get`, `Putall`, `Snarf`, `Cut`,
   `Paste`, `Zerox`, `Sort`, `Load`, `ID`, `Send`, `Tab`, `Indent`, `Local`,