[mirotalksfu] - add comments, fix typo

docker-compose.template.yml

@@ -11,6 +11,8 @@ services:
         restart: unless-stopped
         volumes:
             - ./app/src/config.js:/src/app/src/config.js:ro
+            # These volume is mandatory if server.recording.enabled in the app/src/config.js
+            # - ./app/rec:/src/app/rec
             # These volumes are not mandatory, comment if you want to use it
             # - ./app/:/src/app/:ro
             # - ./public/:/src/public/:ro