title: Send Git commit diffs into gist file
body: <p>I'm aware of the major functions that <code>gist</code> and <code>github</code> can offer even not an in-depth control of all commands.<br/>
  Now I need to maintain some historical changes inot my git repository and What I'm lookin for is, Is there any automatic way (command) to push the git changes in some branch as a .diff into a gist file? Let's say I want to send a pull request in a gist file.<br/>
  Actually I can get the .diff of some commit and copy paste the content into by-hand created gist file.</p>
  
  <p>Any recommandations would be greately appreciated.<br/>
  BR.</p>