Add contribution guide

README.md

@@ -714,6 +714,19 @@ An alternative to endless:
 
 * [manners](https://github.com/braintree/manners): A polite Go HTTP server that shuts down gracefully.
 
+## Contributing 
+
+- With issues:
+  - Use the search tool before opening a new issue.
+  - Please provide source code and commit sha if you found a bug.
+  - Review existing issues and provide feedback or react to them.
+- With pull requests:
+  - Open your pull request against develop
+  - Your pull request should have no more than two commits, if not you should squash them.
+  - It should pass all tests in the available continuous integrations systems such as TravisCI.
+  - You should add/modify tests to cover your proposed code changes.
+  - If your pull request contains a new feature, please document it on the README.
+
 ## Example
 
 Awesome project lists using [Gin](https://github.com/gin-gonic/gin) web framework.