title: Git squash history after merge
body: <p>I merged an upstream of a large project with my local git repo. Prior to the merge I had a small amount of history that was easy to read through, but after the merge a massive amount of history is now in my repo. I have no need for all the history commits from the upstream repo.</p>
  
  <p>There have been other commits made after this upstream merge that I would like to keep. How do I squash all that history that was merged from the upstream into one commit while keeping the commits made after the upstream merge?</p>