add Drawer demo

src/Shared/HandyControl_Shared/Themes/Styles/Base/DrawerBaseStyle.xaml

@@ -0,0 +1,10 @@
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+                    xmlns:controls="clr-namespace:HandyControl.Controls">
+
+    <Style x:Key="DrawerBaseStyle" TargetType="controls:Drawer">
+        <Setter Property="Dock" Value="Right"/>
+        <Setter Property="MaskBrush" Value="{DynamicResource DarkOpacityBrush}"/>
+    </Style>
+
+</ResourceDictionary>