Send writing messages event

lib/helpers/conversations_helper.dart

@@ -404,6 +404,10 @@ class ConversationsHelper {
     }
   }
 
+  /// Send a notification to inform that the user is writing a message
+  static Future<void> sendWritingEvent(int convID) async =>
+      await ws("conversations/is_writing", {"convID": convID});
+
   /// Turn an API response into a ConversationMessage object
   static ConversationMessage apiToConversationMessage(
     Map<String, dynamic> map,