add broadcastMessage

Author: thijstriemstra

src/WebSocket.h

@@ -12,6 +12,9 @@ namespace WebSocket
   /// Handle websocket
   void handle();
 
+  /// Broadcast a message to all active websocket connections
+  void broadcastMessage(String msg);
+
   /// Broadcast the current animation status to all active websocket connections
   void broadcastStatus();