title: How to update a GitHub project downloaded as ZIP file?
body: <p>I have downloaded an archive of some large GitHub repository using <em>Download ZIP</em> link. It contained just the source code, so it wasn't a clone or a git repo anymore. Then I made some changes in this code on my disk and now I want to update it using the code of HEAD revision from the original GitHub repo (which has changed since I downloaded the ZIP file). But it's a large repo, so I don't want to download all the files, but just the modified ones.</p>
  
  <p>Should I <code>git init</code> a new repo in my existing source code folder, then <code>git add .</code> and <code>git commit</code> then <code>git remote add origin https://github.com/someuser/someproject.git</code> and <code>git pull origin master</code>? Will this download only the modified files?</p>