Add How to Cite in FAQ

[amc-corey-cox]

It would be useful for paper authors to be able to easily figure out how OAK would prefer to be cited, even if it is by linking to the GitHub repository.

[matentzn]

Whenever there is nothing obvious to cite, search on Zenodo for a doi: https://zenodo.org/record/8323168

Many of our repos have a doi