add basic files

src/Shared/HandyControl_Shared/Controls/SideMenu/SideMenu.cs

@@ -1,9 +1,13 @@
-using System.Windows.Controls;
+using System.Windows;
 
 namespace HandyControl.Controls
 {
-    public class SideMenu : Control
+    public class SideMenu : HeaderedSimpleItemsControl
     {
+        private SideMenuItem _selectedItem;
 
+        protected override DependencyObject GetContainerForItemOverride() => new SideMenuItem();
+
+        protected override bool IsItemItsOwnContainerOverride(object item) => item is SideMenuItem;
     }
 }