wip: Update example

Author: lijy91

example/lib/main.dart

@@ -19,12 +19,6 @@ class _MyAppState extends State<MyApp> {
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
-      theme: ThemeData(
-        primaryColor: const Color(0xff416ff4),
-        canvasColor: Colors.white,
-        scaffoldBackgroundColor: const Color(0xffF7F9FB),
-        dividerColor: Colors.grey.withOpacity(0.3),
-      ),
       builder: BotToastInit(),
       navigatorObservers: [BotToastNavigatorObserver()],
       home: const HomePage(),