title: Clone a subdirectory of a submodule in git
body: <p>I wish to create a submodule in my repository, and inside that submodule I only want to clone ONE folder to use as a dependency.</p>
  <p><strong>For example if this is my current state:</strong></p>
  <pre><code>main repository
  │__README.md
  │__file001.txt
  </code></pre>
  <pre><code>dependency repository
  |__src
  |__include
  </code></pre>
  <p><strong>I want to have:</strong></p>
  <pre><code>main repository
  │__README.md
  │__file001.txt
  |__dependency repository (submodule)
     |__include
  </code></pre>
  <p>How is it possible to do it in git?</p>