Add profiling in README.md

Author: zd-double

README.md

@@ -51,6 +51,9 @@ For more details, please refer to the wiki [Build Guide](https://github.com/baid
 ### Sample
 For sample code, please refer to ['./sample'](https://github.com/baidu/sofa-pbrpc/tree/master/sample) and the wiki [Quick Start](https://github.com/baidu/sofa-pbrpc/wiki/%E5%BF%AB%E9%80%9F%E4%BD%BF%E7%94%A8).
 
+### Profiling
+For Profiling feature, please refer to the wiki [Profiling](https://github.com/baidu/sofa-pbrpc/wiki/Profiling%E5%8A%9F%E8%83%BD).
+
 ### Performance
 For performace details, please refer to the wiki [Performance](https://github.com/baidu/sofa-pbrpc/wiki/%E6%80%A7%E8%83%BD).