Update README.md

Author: 2534290808

README.md

@@ -1,19 +1,19 @@
 # react-native-SmartRefreshLayout[![npm version](https://badge.fury.io/js/react-native-smartrefreshlayout.svg)](https://badge.fury.io/js/react-native-smartrefreshlayout)
 基于android SmartRefreshLayout https://github.com/scwang90/SmartRefreshLayout 开发的插件，可提供类似ios的弹性刷新、加载
 ## 第一步
-工程目录下运行 npm install --save react-native-smartrefreshlayout 或者 yarn add react-native-smartrefreshlayout(已经安装了yarn)
+工程目录下运行 `npm install --save react-native-smartrefreshlayout` 或者 `yarn add react-native-smartrefreshlayout`(已经安装了yarn)
 ## 第二步
-运行 react-native link react-native-smartrefreshlayout
+运行 `react-native link react-native-smartrefreshlayout`
 ## 第三部使用
 在工程中导入：
-```bash
-import {SmartRefreshControl,ClassicsHeader,StoreHouseHeader} from 'react-native-smartrefreshlayout';
+```js
+import {SmartRefreshControl,ClassicsHeader,StoreHouseHeader,DefaultHeader} from 'react-native-smartrefreshlayout';
 
 //使用方法和RN官方的RefreshControl类似，
 <ScrollView 
   refreshControl={<SmartRefreshControl
      ref={refreshcontrol=>this.refreshControl=refreshcontrol}
-     HeaderComponent={<ClassicsHeader/>}
+     HeaderComponent={<DefaultHeader/>}
      onRefresh={()=>{
        setTimeout(()=>{
        this.refreshControl && this.refreshControl.finishRefresh();