docs: Update 3 files

wikijs/README.txt

@@ -19,6 +19,7 @@ HTTP_PORT       - Web interface port (default: 3080)
 PUID            - User ID for file permissions (default: 1000)
 PGID            - Group ID for file permissions (default: 1000)
 TZ              - Timezone (default: Pacific/Auckland)
+DB_TYPE         - Database type: sqlite or postgres (default: sqlite)
 
 Ports
 -----
@@ -44,10 +45,19 @@ You will be guided through the initial setup wizard to:
 Database
 --------
 
-By default, Wiki.js uses SQLite which requires no additional setup.
-For PostgreSQL support, configure the database settings in the
-Wiki.js admin panel after initial setup, or edit the config.yml
-file directly in DATA_PATH/config/.
+By default, Wiki.js uses SQLite (DB_TYPE=sqlite) which requires no
+additional setup and stores data in DATA_PATH/data/.
+
+For PostgreSQL support, set DB_TYPE=postgres and configure these
+additional environment variables in service.env:
+  DB_HOST  - PostgreSQL server hostname
+  DB_PORT  - PostgreSQL server port (default: 5432)
+  DB_NAME  - Database name
+  DB_USER  - Database username
+  DB_PASS  - Database password
+
+Note: Database settings only apply on first run. After initial setup,
+modify DATA_PATH/config/config.yml directly.
 
 Backup & Restore
 ----------------