Feel free to contribute bug-fixes and new features. If you do so, please apply the Gitflow workflow. This sounds more complicated than it is. Check out the Getting Started to initialize your forked project for Gitflow usage. Then use:
git flow feature start feature_branchwhen contributing a new feature, this is always based on thedevelopbranchgit flow hotfix start hotfix_branchwhen contributing a patch, this is always based on themasterbranch.
Replace feature_branch or hotfix_branch in the above example with a descriptive name. Do not finish the feature or
hotfix, but do a pull request on the new branch.