add NavigationWindow style

src/Shared/HandyControl_Shared/Themes/Styles/NavigationWindow.xaml

@@ -0,0 +1,9 @@
+<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation">
+
+    <ResourceDictionary.MergedDictionaries>
+        <ResourceDictionary Source="Base/NavigationWindowBaseStyle.xaml"/>
+    </ResourceDictionary.MergedDictionaries>
+
+    <Style BasedOn="{StaticResource NavigationWindowBaseStyle}" TargetType="NavigationWindow"/>
+
+</ResourceDictionary>