title: What does this green icon mean in a github repository?
body: <p>What does this green icon mean in Github? I know the commit link takes me to another repository. I need to do something similar. Is this a symlink? Or a submodule? Being still somewhat new to git, I'm wondering how I can replicate this myself. Once created, how do I update this external dependency?</p>
  
  <p><img src="https://i.stack.imgur.com/7Zj6F.png" alt="Git repository - what&#39;s up with the green icon?"></p>