Update README.md

Author: yukirin000

README.md

@@ -18,10 +18,10 @@ npm install jpush-react-native --save
   npm install jcore-react-native --save
   ```
 安装完成后连接原生库
-进入到根目录执行
-react-native link
-或
-react-native link jpush-react-native
+进入到根目录执行<br/>
+react-native link<br/>
+或<br/>
+react-native link jpush-react-native<br/>
 react-native link jcore-react-native
 
 ## 2. 配置