新增骨架屏控件

demo/Ursa.Demo/ViewModels/MainViewViewModel.cs

@@ -36,6 +36,7 @@ public class MainViewViewModel : ViewModelBase
             MenuKeys.MenuKeyPagination => new PaginationDemoViewModel(),
             MenuKeys.MenuKeyTagInput => new TagInputDemoViewModel(),
             MenuKeys.MenuKeyTimeline => new TimelineDemoViewModel(),
+            MenuKeys.MenuKeySkeleton => new SkeletonDemoViewModel(),
         };
     }
 }

demo/Ursa.Demo/ViewModels/MenuViewModel.cs

@@ -23,6 +23,7 @@ public class MenuViewModel: ViewModelBase
             new() { MenuHeader = "Pagination", Key = MenuKeys.MenuKeyPagination },
             new() { MenuHeader = "TagInput", Key = MenuKeys.MenuKeyTagInput },
             new() { MenuHeader = "Timeline", Key = MenuKeys.MenuKeyTimeline },
+            new() { MenuHeader = "Skeleton", Key = MenuKeys.MenuKeySkeleton },
         };
     }
 }

demo/Ursa.Demo/ViewModels/SkeletonDemoViewModel.cs

@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Ursa.Demo.ViewModels
+{
+    public class SkeletonDemoViewModel : ViewModelBase
+    {
+    }
+}