GitHub seems to have updated the achievements feature, so what other achievements are there? Is there a list of achievements and their unlock requirements? Didn't find any documentation and post about this.
While the answer by Smitop is currently correct, there is official documentation including specifics on how the achievements were/are earned, which presumably will be updated with future additions: https://docs.github.com/en/github/setting-up-and-managing-your-github-profile/personalizing-your-profile#displaying-badges-on-your-profile
Also I've created a mirror: https://github.com/Schweinepriester/github-profile-achievements