Please feel free to submit issues and PRs in the repositories where you want to contribute.
Please also read the CONTRIBUTING guidelines in the respective repository.
In general we suggest to create an issue first. We can then have a quick discussion about what needs fixing and how to fix it.
We value that people submit issues. We value PRs that fix the issues even more.
If you are lost or do not know what to do, reach out to us on Gitter.