Update README_zh-CN.md (#404)

correct FAQ url

README_zh-CN.md

@@ -334,7 +334,7 @@ TODO
 # FAQ
 [常见问题](docs/FAQ_zh_cn.md)
 
-[FAQ](docs/FAQ.md)
+[FAQ](docs/FAQ_en_us.md)
 
 
 # All Thanks To Our Contributors