Refine .env.example files across all stacks

- Streamline variable organization and formatting
- Reduce redundant comments and improve clarity
- Maintain all required variables for each stack

docker-compose/wikis/.env.example

@@ -1,18 +1,14 @@
 # Wikis Stack Environment Variables
-# These variables are used for wiki and documentation platforms
 
-# Base Configuration
-DOMAIN=
 TZ=
-
-# User Configuration
 PUID=
 PGID=
+SERVER_IP=
+SERVER_HOSTNAME=
+DOMAIN=
 
-# BookStack Database Configuration
 BOOKSTACK_DB_PASSWORD=
 BOOKSTACK_DB_ROOT_PASSWORD=
 
-# MediaWiki Database Configuration
 MEDIAWIKI_DB_PASSWORD=
 MEDIAWIKI_DB_ROOT_PASSWORD=