Migrate menu to blueprint

src/window.blp

@@ -4,4 +4,23 @@ using Adw 1;
 template TutorialWindow : Adw.ApplicationWindow {
   default-width: 800;
   default-height: 600;
+}
+
+menu primary_menu {
+  section {
+    item {
+      label: _("Preferences");
+      action: "app.preferences";
+    }
+
+    item {
+      label: _("Keyboard Shortcuts");
+      action: "win.show-help-overlay";
+    }
+
+    item {
+      label: _("About");
+      action: "app.about";
+    }
+  }
 }

src/window.ui

@@ -23,7 +23,7 @@
           <object class="GtkLabel" id="label">
             <property name="label">Hello, World!</property>
             <style>
-              <class name="title-1"/>org.freedesktop.Sdk.Extension.rust-stable/aarch64/45
+              <class name="title-1"/>
             </style>
           </object>
         </property>