Thank you for thinking about contributing to this project. This document will help you to get started.
If you'd like to add a feature to Avatar (or modify its existing behaviour), please start by creating an issue so we can discuss it. Don't go straight to a pull request in case it's something I don't wish to accept; I don't want to waste your time.
If you've found a bug, please start by creating an issue. If you'd like to make a pull request for the fix once I've confirmed it's a bug in Avatar, that would be great.