Looking for your personal lists of Github repositories, which might be deleted from Github at some point, for whatever reason. For example, the maintainer might delete his account from Github or archive all his repositories.
A famous example of an open source project, which had trouble to continue thriving, is youtube-dl.
Which projects’ repositories do you think are worth backing up?
You can easily mirror Github wikis as well. You just need to add
.wiki.gitto the repo URL. That way you can clone the wiki just like any other Git repo.