更新心跳註解

HeartbeatSender.cs

@@ -1,4 +1,3 @@
-using System;
 using System.Net;
 using System.Net.Sockets;
 using System.Text;
@@ -15,6 +14,7 @@ namespace HeartbeatSender{
             udpClient = new UdpClient();
             // 設置 IP 和 PORT
             remoteEndPoint = new IPEndPoint(IPAddress.Parse(targetIp), targetPort);
+            // 每3秒發送一次
             heartbeatTimer = new System.Timers.Timer(intervalMilliseconds);
             heartbeatTimer.Elapsed += SendHeartbeat;
             heartbeatTimer.AutoReset = true;