Add Notification Event Response Property (#7155)

* Add Notification Event Response Property

* Update notifications.md

Co-authored-by: Taylor Otwell <[email protected]>

Author: lucaxue

notifications.md

@@ -1176,7 +1176,7 @@ When a notification is sent, the `Illuminate\Notifications\Events\NotificationSe
 
 > {tip} After registering listeners in your `EventServiceProvider`, use the `event:generate` Artisan command to quickly generate listener classes.
 
-Within an event listener, you may access the `notifiable`, `notification`, and `channel` properties on the event to learn more about the notification recipient or the notification itself:
+Within an event listener, you may access the `notifiable`, `notification`, `channel`, and `response` properties on the event to learn more about the notification recipient or the notification itself:
 
     /**
      * Handle the event.