[linting_tool] Add Adaptive Layout with Theming (#852)

experimental/linting_tool/lib/main.dart

@@ -3,67 +3,8 @@
 // found in the LICENSE file.
 
 import 'package:flutter/material.dart';
+import 'package:linting_tool/app.dart';
 
 void main() {
-  runApp(MyApp());
-}
-
-class MyApp extends StatelessWidget {
-  @override
-  Widget build(BuildContext context) {
-    return MaterialApp(
-      title: 'Flutter Linting Tool',
-      theme: ThemeData(
-        primarySwatch: Colors.blue,
-      ),
-      home: const MyHomePage(title: 'Flutter Linting Tool'),
-    );
-  }
-}
-
-class MyHomePage extends StatefulWidget {
-  const MyHomePage({Key? key, required this.title}) : super(key: key);
-
-  final String title;
-
-  @override
-  _MyHomePageState createState() => _MyHomePageState();
-}
-
-class _MyHomePageState extends State<MyHomePage> {
-  int _counter = 0;
-
-  void _incrementCounter() {
-    setState(() {
-      _counter++;
-    });
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(
-        title: Text(widget.title),
-      ),
-      body: Center(
-        child: Column(
-          mainAxisAlignment: MainAxisAlignment.center,
-          children: <Widget>[
-            const Text(
-              'You have pushed the button this many times:',
-            ),
-            Text(
-              '$_counter',
-              style: Theme.of(context).textTheme.headline4,
-            ),
-          ],
-        ),
-      ),
-      floatingActionButton: FloatingActionButton(
-        onPressed: _incrementCounter,
-        tooltip: 'Increment',
-        child: const Icon(Icons.add),
-      ),
-    );
-  }
+  runApp(const LintingTool());
 }