zio fork 1.8.2b-zio5: staff chat shows rank

@ in team chat and css_asay read ">[STAFF][RANK] name: message", and @ in all chat and a
player's css_say read ">[RANK] name: message", with the rank from the sender's highest #rank/...
group (O, SA, A, TA, M, TM, H). Staff in no rank group get ">[STAFF] name" and "> name". A
non-staff player's @ team chat reads ">[PLAYER] name: message". Console's messages are unchanged.
The lines are new en.json keys: sa_staffchat_template, sa_staffsay_template, their _norank
variants and sa_staffchat_template_player.

README.md

@@ -14,6 +14,13 @@ from the `build-1.8.2b` tag). Changes, all marked `zio:` in the code:
 - New permission `@css/bypassipban`, for players or groups: IP bans, and bans on other accounts
   that share their IP, don't apply to them; a ban on their own SteamID still does. `@css/root`
   has it, as it has every `@css` flag.
+- Staff chat shows the sender's rank, from their highest `#rank/...` group (O, SA, A, TA, M, TM,
+  H for helper): `@message` in team chat and `css_asay` read `>[STAFF][RANK] name: message`, and
+  `@message` in all chat and `css_say` from a player read `>[RANK] name: message` (`> name: message`
+  if they have no rank group). A non-staff player's `@message` in team chat reads
+  `>[PLAYER] name: message`. Console's `css_say`/`css_asay` are unchanged. New lang keys
+  `sa_staffchat_template`, `sa_staffsay_template`, their `_norank` variants and
+  `sa_staffchat_template_player`, in `lang/en.json` only.
 
 Publish with `FORGEJO_TOKEN=... ./release.sh v<ModuleVersion>` (ModuleVersion is `1.8.2b-zioN`).
 It rebuilds from the committed source and uploads `SimpleAdmin-<tag>.tar.gz` to git.zio.sh