Update CONTRIBUTING.md

CONTRIBUTING.md

@@ -1,18 +1,3 @@
 # How to Contribute
 
-So you want to contribute to the project. **THIS IS GREAT NEWS!**  Seriously. We're
+All of the [instructions for contributing from the main repository](https://github.com/caskroom/homebrew-cask/blob/master/CONTRIBUTING.md) apply, and won't be repeated here. You simply need to change references to `caskroom/homebrew-cask` (that repository) to `caskroom/homebrew-versions` (this repository).
-all pretty happy about this. All of the [instructions for contributing from 
-the homebrew-cask project](https://github.com/caskroom/homebrew-cask/blob/master/CONTRIBUTING.md)
-apply, and won't be repeated here. The only changes concern getting set up to
-contribute:
-
-## Getting set up to contribute
-
-1. Fork the repository in GitHub with the 'Fork' button
-2. Add your GitHub fork as a remote for your homebrew-cask Tap
-
-```bash
-github_user='<my-github-username>'
-cd $(brew --prefix)/Library/Taps/caskroom/homebrew-versions
-git remote add $github_user https://github.com/$github_user/homebrew-versions
-```