title: Git_GitHub Fork only master branch of a repo
body: <p>I'm working on <a href="https://github.com/openhwgroup/cv32e40p" rel="nofollow noreferrer">this</a> project. As it is fairly big, the upstream repo has quite a few branches, but what I really care about is the master branch. I need to fork the repo and create a new branch, starting from actual status of master. I don't care about all otheres "work in progress" branches, I will have my own branches.</p>
  
  <p>Is there a way to fork the repo, but only the master branch, to keep things clean from my perspective.
  Would this cause problems if later I try to issue a merge request?</p>
  
  <p>Thanks,
  Andrea</p>