README updated.

Author: aarkalyk

README.md

@@ -245,6 +245,7 @@ class RNCallKitExample extends React.Component {
     RNCallKit.addEventListener('answerCall', this.onRNCallKitPerformAnswerCallAction);
     RNCallKit.addEventListener('endCall', this.onRNCallKitPerformEndCallAction);
     RNCallKit.addEventListener('didActivateAudioSession', this.onRNCallKitDidActivateAudioSession);
+    RNCallKit.addEventListener('didDisplayIncomingCall', this.onRNCallKitDidDisplayIncomingCall);
   }
 
   onRNCallKitDidReceiveStartCallAction(data) {
@@ -285,6 +286,12 @@ class RNCallKitExample extends React.Component {
      */
   }
 
+  onRNCallKitDidDisplayIncomingCall(error) {
+    /* You will get this event after RNCallKit finishes showing incoming call UI
+     * You can check if there was an error while displaying
+     */
+  }
+
   // This is a fake function where you can receive incoming call notifications
   onIncomingCall() {
     // Store the generated uuid somewhere