I can only speak for myself but I prefer not to manually onboard new contributors. I'd rather do a near-infinite number other things with that time.
Add a contributors guide, link to it in your README. GH even has some functionality built-in to link to it these days. Help contributors help themselves and spend that time on something else.
Well the alternative is to deal with poor/unresearched PRs, or to not accept volunteer contributions at all (which is what I do with most of my own open-source projects.)
Add a contributors guide, link to it in your README. GH even has some functionality built-in to link to it these days. Help contributors help themselves and spend that time on something else.