Add chapter 10 sample project

Chapter10/TemplateStudioSampleApp/Contracts/Services/INavigationViewService.cs

@@ -0,0 +1,22 @@
+using Microsoft.UI.Xaml.Controls;
+
+namespace TemplateStudioSampleApp.Contracts.Services;
+
+public interface INavigationViewService
+{
+    IList<object>? MenuItems
+    {
+        get;
+    }
+
+    object? SettingsItem
+    {
+        get;
+    }
+
+    void Initialize(NavigationView navigationView);
+
+    void UnregisterEvents();
+
+    NavigationViewItem? GetSelectedItem(Type pageType);
+}