title: Issue with open and running already existing Magnolia-CMS project
body: <p>I started looking at the Magnolia CMS system and found a project on the web and I can't open it and run it.
  This are the files:</p>
  <h2><code>author.tar</code></h2>
  <h2><code>magnolia.tar.xz</code></h2>
  <h2><code>public.tar.xz</code></h2>
  <h2><code>magnolia.tar</code></h2>
  <p>I tried to add the files into apache folder and run it, I tried with Magnolia CLI to run it, but with no success.
  I miss something, but I'm completely new to Magnolia, so I have no idea.
  Thanks in advance.</p>