title: how to add folder to subfolder inside existing zip file
body: <p>I want to achieve the following (simple) task, but I don't know how...</p>
  
  <p>I have a zip file like this, only containing some folders</p>
  
  <p><strong>dummy.zip:</strong></p>
  
  <pre><code>/my/dummy/folder/stucture
  </code></pre>
  
  <p>how can I add folders to this dummy.zip file that the newly added files and dirs are located under "/my/dummy/folder/stucture" using the command line (linux)?</p>
  
  <p><strong>dummy.zip</strong> should look like this afterwards:</p>
  
  <pre><code>/my/dummy/folder/stucture/my/new/Dirs
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/ipqzE.jpg" rel="noreferrer">I've made a screenshot to better illustrate what I mean</a></p>