Implement the automatic update check and installation

lib/pages/MainApp.dart

@@ -0,0 +1,28 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/widgets.dart';
+import 'package:timetrack/pages/HomePage.dart';
+
+class MainApp extends StatefulWidget {
+  MainApp({super.key});
+
+  @override
+  State<StatefulWidget> createState() {
+    return MainAppState();
+  }
+}
+
+class MainAppState extends State<MainApp> {
+  @override
+  void didChangeDependencies() {
+    super.didChangeDependencies();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      title: "Time Tracker",
+      routes: {"/": (ctx) => HomePage()},
+      theme: ThemeData.dark(),
+    );
+  }
+}