add PropertyGrid Demo

src/Shared/HandyControl_Shared/Interactivity/Commands/ControlCommands.cs

@@ -171,5 +171,15 @@ namespace HandyControl.Interactivity
         ///     开始截图
         /// </summary>
         public static StartScreenshotCommand StartScreenshot { get; } = new StartScreenshotCommand();
+
+        /// <summary>
+        ///     按照类别排序
+        /// </summary>
+        public static RoutedCommand SortByCategory { get; } = new RoutedCommand(nameof(SortByCategory), typeof(ControlCommands));
+
+        /// <summary>
+        ///     按照名称排序
+        /// </summary>
+        public static RoutedCommand SortByName { get; } = new RoutedCommand(nameof(SortByName), typeof(ControlCommands));
     }
 }