It's all manual now but not that hard. Buried in Quicklisp are the locations of all its repos. The reason I haven't automated it is I don't know if there's a Github API for "Please fork this URI into my account if that's not already done." (Plus not every repo is on Github, and not every QL repo is a proper repo.) I haven't bothered to look into automating it because I don't use that many QL libraries, so manual operation is fine for me. Happy to work with you if you want to try to automate the process.