docs: fix config path in rules-mod CLAUDE.md

Config is in world/serverconfig/ not config/
Applies to all three versions (1.16.5, 1.20.1, 1.21.1)
README in NextCloud also updated.

services/rules-mod/CLAUDE.md

@@ -8,6 +8,9 @@
 ## What This Mod Does
 Player types `/rules` → mod fetches rules from a Discord message → displays in-game with colored formatting. Admins update rules by editing a Discord message — no restarts, no file editing.
 
+## Config Location
+Config file is created at `world/serverconfig/firefrostrules-server.toml` — NOT in `config/`. This applies to all three versions.
+
 ## 7 Source Files (each version)
 - ServerRules.java — main mod class
 - ServerRulesConfig.java — TOML config (bot token, channel ID, message ID)