Update README_CN.md

README_CN.md

 [![](https://jitpack.io/v/elinkthings/BodyFatScaleSDKRepositoryAndroid.svg)](https://jitpack.io/#elinkthings/BodyFatScaleSDKRepositoryAndroid)
 
 [aar包下载地址](https://github.com/elinkthings/BodyFatScaleSDKRepositoryAndroid/releases)
+
 [key申请地址](http://sdk.aicare.net.cn)
+
 [English documentation](README.md)
 
 
 ## 目录
+
 [toc]
 
 ## 概述
 
 官网：www.elinkthings.com
 
-邮箱：app@elinkthings.com
+邮箱：app@elinkthings.com