added stylecop (#1933)

* added stylecop

* removed xml documentation

* used common stylecop file

src/core/Microsoft.PowerToys.Settings.UI.Lib/IPowerToySettings.cs

@@ -1,4 +1,8 @@
-using System;
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
 using System.Collections.Generic;
 using System.Text;
 
@@ -7,7 +11,9 @@ namespace Microsoft.PowerToys.Settings.UI.Lib
     public interface IPowerToySettings
     {
         string name { get; set; }
+
         string version { get; set; }
+
         string ToJsonString();
     }
 }