We happily accept pull requests. For new features, it's best to start an issue and invite contributers to discuss it with you. When you are adding a new maker, no discussion is necessary. Feel free to use other makers as a template and simply create a pull request.
If you have contributed several times or are having trouble getting eyes on helpful bug fixes or new features, you may want to request access to the repository so that you can merge pull requests yourself. We are currently looking to build a team of maintainers so that things can get merged quickly. We would love to hear from you if you are interested. Even if you don't plan on working on the plugin daily or even weekly, you may be able to help a lot. Simply contact one of the organization owners.