add medium icon

Author: Mohit-15

_includes/author-profile.html

@@ -117,7 +117,10 @@ <h3 class="author__name">{{ author.name }}</h3>
       {% endif %}
       {% if author.wikipedia %}
         <li><a href="https://en.wikipedia.org/wiki/User:{{ author.wikipedia }}"><i class="fab fa-fw fa-wikipedia-w" aria-hidden="true"></i> Wikipedia</a></li>
-{% endif %}
+      {% endif %}
+      {% if author.medium %}
+        <li><a href="{{ author.medium }}"><i class="fab fa-fw fa-medium" aria-hidden="true"></i> Medium</a></li>
+      {% endif %}
     </ul>
   </div>
 </div>