📝 add build step

Author: mzp

README.md

@@ -6,6 +6,14 @@ Slack☆Stack is multi-column/multi-row slack client to overview many channels a
 ## :star: Usage
 :construction:
 
+## :wrench: build
+
+```sh
+bundle install
+bundle exec pod install
+bundle exec gym
+```
+
 ## :pray: Acknowleadge
 Icons made by [Freepik](http://www.freepik.com) from [www.flaticon.com](http://www.flaticon.com) is licensed by [CC 3.0 BY](http://creativecommons.org/licenses/by/3.0/).