First off all, thank you for taking the time to contribute!
When contributing to this project, please first discuss the changes you wish to make via an issue before making changes.
Unsure where to begin contributing? You can start by looking through the help wanted issues.
This repo is intended to be used as a git submodule. So, the best approach is to use it this way.
Follow the README instructions on how to use this submodule on your extension.
Be sure your branch is up to date (relative to master) and submit your PR. Also add reference to the issue the PR refers to.