Deprecate the livekit.livekit_service_url config option

Homeservers should advertise their transports over the MSC4143
rtc/transports endpoint instead of relying on a fallback in the app
config.

src/config/ConfigOptions.ts

@@ -97,11 +97,19 @@ export interface ConfigOptions {
     };
   };
 
-  // Describes the LiveKit configuration to be used.
+  /**
+   * Describes the LiveKit configuration to be used.
+   */
   livekit?: {
-    // The link to the service that returns a livekit url and token to use it.
-    // This is a fallback link in case the homeserver in use does not advertise
-    // a livekit service url over the transports endpoint.
+    /**
+     * The link to the service that returns a livekit url and token to use it.
+     * This is a fallback link in case the homeserver in use does not advertise
+     * a livekit service url over the transports endpoint.
+     *
+     * @deprecated Homeservers should advertise available transports over the
+     *   /_matrix/client/unstable/org.matrix.msc4143/rtc/transports endpoint
+     *   instead.
+     */
     livekit_service_url: string;
   };