doc: Add docs for enableLipSync. (#8195)

* doc: Add docs for enableLipSync.

config.js

     // If set to true all muting operations of remote participants will be disabled.
     // disableRemoteMute: true,
 
+    // Enables support for lip-sync for this client (if the browser supports it).
+    // enableLipSync: false
+
     /**
      External API url used to receive branding specific information.
      If there is no url set or there are missing fields, the defaults are applied.
      disableAP
      disableHPF
      disableNS
-     enableLipSync
      enableTalkWhileMuted
      forceJVB121Ratio
      hiddenDomain