main menu action

lib/providers/menu_selection_provider.dart

@@ -0,0 +1,12 @@
+import 'package:flutter/material.dart';
+
+class MenuSelectionProvider with ChangeNotifier {
+  int _selectedIndex = 0;
+
+  int get selectedIndex => _selectedIndex;
+
+  set selectedIndex(int index) {
+    _selectedIndex = index;
+    notifyListeners();
+  }
+}