new startup process UI for Windows

windows/WinUI/CentralServer.cs

@@ -0,0 +1,23 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Newtonsoft.Json;
+
+namespace WinUI
+{
+    class CentralServer
+    {
+        public CentralServer()
+        {
+            ServerURL = "https://my.zerotier.com";
+        }
+
+        [JsonProperty("server_url")]
+        public string ServerURL { get; set; }
+
+        [JsonProperty("api_key")]
+        public string APIKey { get; set; }
+    }
+}