Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -1,13 +1,37 @@
-# Contributing to Motif
+Contributing to Motif
+=======================
 
-To contribute, simply open a pull request. If you'd like to discuss a change before submitting a pull request, open a GitHub Issue describing the proposal.
+The Uber team welcomes contributions of all kinds, from simple bug reports through documentation, test cases,
+bugfixes, and features.
 
-# Building / Testing
+Workflow
+--------
+
+We love GitHub issues!
+
+For small feature requests, an issue first proposing it for discussion or demo implementation in a PR suffice.
+
+For big features, please open an issue so that we can agree on the direction, and hopefully avoid 
+investing a lot of time on a feature that might need reworking.
+
+Small pull requests for things like typos, bugfixes, etc are always welcome.
+
+DOs and DON'Ts
+--------------
+
+* DO include tests when adding new features. When fixing bugs, start with adding a test that highlights how the current behavior is broken.
+* DO keep the discussions focused. When a new or related topic comes up it's often better to create new issue than to side track the discussion.
+* DO run all Gradle verification tasks (`./gradlew check`) before submitting a pull request
+
+* DON'T submit PRs that alter licensing related files or headers. If you believe there's a problem with them, file an issue and we'll be happy to discuss it.
+
+Building / Testing
+------------------
 
 The following will build and test all modules:
 
 `./gradlew build`
 
 Integration tests exist in the `:it` module. To run integration tests:
 
-`./gradlew :compiler:test`
+`./gradlew :compiler:test`