Contributing can be a lot more than just PRs though: - answering questions on stack overflow, chat (irc, gitter, slack)
- creating a minimal code repro, checking for duplicates, checking if a bug is fixed in a later release/master branch
- writing tutorials/usage scenarios, giving talks, just using the project and providing feedback
- helping with documentation + website
- translations if possible
- reviewing other PRs
- helping with the changelog, testing prereleases
- adding to the discussion on issues
Bigger projects can have a pretty hard time with maintenance: fixing bugs, juggling PRs, making releases, answering questions, etc.
(We're looking for help on https://github.com/babel/babel and trying to figure out how we can make the project more contributor friendly!)