Add freiheit.com to list of sponsors

Author: flodiebold

index.html

@@ -53,6 +53,7 @@ <h2>Support</h2>
             <li><a href="https://ferrous-systems.com/">Ferrous Systems</a></li>
             <li><a href="https://www.mozilla.org/">Mozilla</a></li>
             <li><a href="https://embark-studios.com">Embark Studios</a></li>
+            <li><a href="https://www.freiheit.com/">freiheit.com</a></li>
         </ul>
     </p>