title: Giving access to parts of a github repository
body: <p>I have a repository on Github for which I would like to give access to a freelancer.</p>
  
  <p>I can't give them access to the entire codebase for security reasons, but I would like to be able to merge their changes from the sections that I do give them access to.</p>
  
  <p>If I create a fork and remove the restricted files then it still has the history available, so that doesn't really work.</p>
  
  <p>What would be the best way to go about this?</p>