I'm really glad you're reading this, because we need volunteer developers to help this project come to fruition.
Here are some important resources:
You can add the repo, then make local changes (making ebuilds). Then you can test install it into your local device. If you're sure it works, proceed to the next step!
Please send a GitHub Pull Request to us with a clear list of what you've done (read more about pull requests).
Always write a clear log message for your commits. One-line messages are fine for small changes, but bigger changes should look like this:
$ git commit -m "A brief summary of the commit
>
> A paragraph describing what changed and its impact."
Thanks, Parin