Settings page added

lib/theme_provider.dart

@@ -0,0 +1,12 @@
+import 'package:flutter/material.dart';
+
+class ThemeProvider extends ChangeNotifier{
+  ThemeMode themeMode = ThemeMode.dark;
+
+  bool get isDarkMode => themeMode == ThemeMode.dark;
+
+  void toggleTheme(bool isOn){
+    themeMode = isOn ? ThemeMode.dark : ThemeMode.light;
+    notifyListeners();
+  }
+}