Update README.md

Author: mincong-h

README.md

@@ -91,6 +91,7 @@ Java unit tests. https://site.mockito.org
 ### Reliability
 
 - [Create a Throttler in Java](https://mincong.io/2020/11/07/throttler/)
+- [Feature Flag: Making Your Application More Reliable](https://mincong.io/2020/11/11/feature-flag/)
 
 ## Code Style