add screenutil support

example/lib/main.dart

@@ -1,3 +1,4 @@
+import 'package:ansu_ui/ansu_ui.dart';
 import 'package:ansu_ui/buttons/as_button.dart';
 import 'package:flutter/material.dart';
 
@@ -6,9 +7,10 @@ void main() {
 }
 
 class MyApp extends StatelessWidget {
-  // This widget is the root of your application.
   @override
   Widget build(BuildContext context) {
+    ScreenUtil.init(context,
+        designSize: Size(750, 1334), allowFontScaling: false);
     return MaterialApp(
       title: 'Flutter Demo',
       theme: ThemeData(
@@ -60,6 +62,7 @@ class _MyHomePageState extends State<MyHomePage> {
       body: ListView(
         children: [
           ASButton(),
+          SizedBox(height: 12.w),
         ],
       ),
     );

example/pubspec.lock

@@ -69,6 +69,13 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  flutter_screenutil:
+    dependency: transitive
+    description:
+      name: flutter_screenutil
+      url: "https://pub.flutter-io.cn"
+    source: hosted
+    version: "3.2.0"
   flutter_test:
     dependency: "direct dev"
     description: flutter

lib/ansu_ui.dart

@@ -1,3 +1,4 @@
 library ansu_ui;
 
 export 'buttons/as_button.dart';
+export 'package:flutter_screenutil/flutter_screenutil.dart';

pubspec.lock

@@ -55,6 +55,13 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  flutter_screenutil:
+    dependency: "direct main"
+    description:
+      name: flutter_screenutil
+      url: "https://pub.flutter-io.cn"
+    source: hosted
+    version: "3.2.0"
   flutter_test:
     dependency: "direct dev"
     description: flutter

pubspec.yaml

@@ -2,7 +2,6 @@ name: ansu_ui
 description: A new Flutter package.
 version: 0.0.1
 author:
-homepage:
 
 environment:
   sdk: ">=2.7.0 <3.0.0"
@@ -11,6 +10,7 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
+  flutter_screenutil: ^3.2.0
 
 dev_dependencies:
   flutter_test:
@@ -21,7 +21,6 @@ dev_dependencies:
 
 # The following section is specific to Flutter.
 flutter:
-
   # To add assets to your package, add an assets section, like this:
   # assets:
   #   - images/a_dot_burr.jpeg
@@ -32,7 +31,6 @@ flutter:
   #
   # An image asset can refer to one or more resolution-specific "variants", see
   # https://flutter.dev/assets-and-images/#resolution-aware.
-
   # To add custom fonts to your package, add a fonts section here,
   # in this "flutter" section. Each entry in this list should have a
   # "family" key with the font family name, and a "fonts" key with a