title: How to copy specific files from one git repo to another, preserving history
body: <p>I have an old private repo with files I'd like to put in GitHub, however I'd like to only include certain files or perhaps only files with certain file extensions, along with their commit history.</p>
  
  <p>However I don't want to include any of the excluded files in the commit history.</p>
  
  <p>I guess it would be ideal to provide a file of list of such files I'd like to copy.</p>