style(ui_kit): remove default files

packages/wyatt_ui_kit/example/lib/main.dart

@@ -16,8 +16,6 @@
 
 import 'package:flutter/material.dart';
 
-import 'package:wyatt_ui_kit/wyatt_ui_kit.dart';
-
 void main(List<String> args) {
   runApp(const App());
 }
@@ -37,7 +35,6 @@ class App extends StatelessWidget {
           appBar: AppBar(
             title: const Text(title),
           ),
-          body: Center(child: Text(WyattUiKit.testString)),
         ),
       );
 }