Merge pull request #88 from webxdc/r10s/update-api-availability

update realtime API availability

src-docs/spec/joinRealtimeChannel.md

@@ -22,10 +22,7 @@ will throw an error.
 
 This API is experimental and may not be implemented by every messenger yet.
 Check if it is available with `window.webxdc.joinRealtimeChannel !== undefined`
-
-For Delta Chat, you need at least version 1.46 to enable the feature
-in the settings under `Settings -> Advanced -> Experimental Features -> Realtime Webxdc Channels`.
-Without enabling the feature, the API is available but not working.
+(for Delta Chat, the API is available and enabled by default since 1.48)
 
 ## `realtimeChannel.setListener((data) => {})`