title: GitHub fork a repo from previous commit
body: <p>I've found a repository on GitHub I would like to fork - but not the current version.</p>
  
  <p>I want to fork the repo as it was quite a few commits back - is this possible? The repo has not marked any releases, so I'm not sure how to do this. I could obviously copy the code as it was in that commit, but I would prefer to fork, as then I get the link back to the original repo.</p>