Add Tincho to the list of consultants (#741)

I was told that it was OK to directly sending a PR for this. Please, let me know if it is not.

content/community.html

@@ -75,6 +75,7 @@ title: Community
       <li><a href="https://www.robustperception.io">Robust Perception</a></li>
       <li><a href="http://juliusv.com">Julius Volz</a> (independent contractor)</li>
       <li><a href="https://container-solutions.com">Container Solutions</a></li>
+      <li><a href="https://tincho.org">Martín Ferrari</a> (independent contractor)</li>
     </ul>
 
     <h1>Acknowledgements</h1>