docs: the nameplate row count is twenty-one, not seventeen

Ten friendly names and five hostile ones are the per-kind switches, plus
`nameplateMaxDistance` — sixteen live — and five more registered and inert.
The previous commit's message carries the same wrong total; this is the
correction, since the doc is the thing anyone reads later.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SgstFWtn1RxEJ5kVrpgYwn

docs/ADDON_COMPAT.md

@@ -2124,7 +2124,7 @@ setting", and the row goes grey. The session log named the whole set, one line e
 ```
 ui_script: unknown CVar 'nameplateShowFriendlyNPCs' (not host-registered) — ignored
 ui_script: unknown CVar 'nameplateShowFriendlyPlayers' …
-ui_script: unknown CVar 'nameplateShowEnemyPlayers' …            (17 nameplate rows in all)
+ui_script: unknown CVar 'nameplateShowEnemyPlayers' …            (21 nameplate rows in all)
 ```
 
 The two rows that *did* work were the two whose `PLATE_KIND_CVARS` entry happens to name
@@ -2132,7 +2132,7 @@ The two rows that *did* work were the two whose `PLATE_KIND_CVARS` entry happens
 because 1.12 has no nameplate CVar at all and those two names were borrowed from later clients to
 persist its `[0xc4da34]` bitmask.
 
-Seventeen rows are registered now. Sixteen of them are live: friendly players, friendly NPCs,
+Twenty-one rows are registered now. Sixteen of them are live: friendly players, friendly NPCs,
 hostile players, and the pets/guardians/totems/minions of each side — eight names on the friendly
 side and four on the hostile one, each side driving **one** field, because a 1.12 object update
 carries an owner and not a kind of owner, and because an addon that means "show them" writes the