docs: 📝 update configuration doc (#195)

docs/source/configuration.md

@@ -10,18 +10,22 @@ you happen to delete it, there shouldn't be any serious consequence either.
 There are a number of settings that you can change:
 
 ```bash
+# To enable or disable RTC(Real-Time Collaboration) (default: False).
+# If True, RTC will be disabled.
+jupyter lab --YDocExtension.disable_rtc=True
+
 # The delay of inactivity (in seconds) after which a document is saved to disk (default: 1).
 # If None, the document will never be saved.
-jupyter lab --collaborative --YDocExtension.document_save_delay=0.5
+jupyter lab --YDocExtension.document_save_delay=0.5
 
 # The period (in seconds) to check for file changes on disk (default: 1).
 # If 0, file changes will only be checked when saving.
-jupyter lab --collaborative --YDocExtension.file_poll_interval=2
+jupyter lab --YDocExtension.file_poll_interval=2
 
 # The delay (in seconds) to keep a document in memory in the back-end after all clients disconnect (default: 60).
 # If None, the document will be kept in memory forever.
-jupyter lab --collaborative --YDocExtension.document_cleanup_delay=100
+jupyter lab --YDocExtension.document_cleanup_delay=100
 
 # The YStore class to use for storing Y updates (default: JupyterSQLiteYStore).
-jupyter lab --collaborative --YDocExtension.ystore_class=ypy_websocket.ystore.TempFileYStore
+jupyter lab --YDocExtension.ystore_class=ypy_websocket.ystore.TempFileYStore
 ```