update readme 5.0+2

@@ -14,9 +14,7 @@ class MyApp extends StatelessWidget {
         title: 'Flutter_ScreenUtil',
         theme: ThemeData(
           primarySwatch: Colors.blue,
-          textTheme: TextTheme(
-            button: TextStyle(fontSize: 45.sp)
-          ),
+          textTheme: TextTheme(button: TextStyle(fontSize: 45.sp)),
         ),
         builder: (context, widget) {
           return MediaQuery(

@@ -66,7 +66,9 @@ class _HomePageState extends State<HomePage> {
                   child: Text(
                       '我的设计稿宽度: 180dp \n'
                       '我的设计稿高度: 200dp',
-                      style: TextStyle(color: Colors.white, fontSize: ScreenUtil().setSp(12))),
+                      style: TextStyle(
+                          color: Colors.white,
+                          fontSize: ScreenUtil().setSp(12))),
                 ),
               ],
             ),