add known user

README.md

@@ -213,3 +213,4 @@ The project is licensed under the [Apache 2 license](https://github.com/ctripcor
 ![汽车之家](https://raw.githubusercontent.com/ctripcorp/apollo/master/doc/images/known-users/autohome.png) 
 ![面包财经](https://raw.githubusercontent.com/ctripcorp/apollo/master/doc/images/known-users/mbcaijing.png) 
 ![虎扑](https://raw.githubusercontent.com/ctripcorp/apollo/master/doc/images/known-users/hoopchina.png) 
+![搜狐汽车](https://raw.githubusercontent.com/ctripcorp/apollo/master/doc/images/known-users/sohu-auto.png)