title: Git: how to push submodule to a remote repository?
body: <p>I use git to track website I'm working on. I work on my machine and push commits to a remote server configured following this guide: <a href="http://toroid.org/ams/git-website-howto" rel="noreferrer">using Git to manage a website</a>.</p>
  
  <p>Last week I tried using Git submodules to manage some third party libraries and today I tried pushing to the server, finding out that in the server all the submodule directories are empty.</p>
  
  <p>I tried adding and commiting changes to the local submodule, indeed <code>git status</code> says that the working directory is clean.</p>
  
  <p>What can I do?</p>