title: How to move Git submodule to sub-directory?
body: <p>guys, I just used submodule to organize some Git repos, here's the address:
  <a href="https://github.com/shawjia/repos">repos</a></p>
  
  <p>I want to move all the submodule into a new directory called repos, for examples, jquery -> repos/jquery.</p>
  
  <p>I change the <strong>.gitmodules</strong> file, but seems it doesn't work.
  What should I do?</p>