add demo readme

.gitignore

@@ -1,3 +1,2 @@
 *.pyc
 .DS_Store
-design/*/scripts/

README.md

@@ -10,11 +10,15 @@ It can also help EDA researchers and tool developer do research on new design me
 ## Dependency
  - python3
  - [Yosys](https://github.com/YosysHQ/yosys)
- - [Hpyeropt](https://github.com/hyperopt/hyperopt)
+ - [Hpyeropt](https://github.com/hyperopt/hyperopt)(optional for tuning)
  - genus (optional)
  - innovus (optional)
  
 ## Demo
+ 1. Branch Flow
+ 	python3 demo/branch/flow.py
+ 2. Flow Tuning
+ 	python3 demo/tuner/main.py
  
 ## Ongoing work
  - Integrating other open source binaries