Fix broken YouTube link.

Author: thomasjbradley

index.html

@@ -72,7 +72,7 @@ <h2 class="mega push-1-2"><a href="https://github.com/acgd-learn-the-web">Learn
       </a>
     </li>
     <li class="list-group__item-inline">
-      <a class="icon-link" href="https://youtube.com/algonquindesign" rel="external">
+      <a class="icon-link" href="https://www.youtube.com/user/acinteractivedesign" rel="external">
         <i class="icon i--16 i-youtube"></i>
         <span class="icon__text">YouTube</span>
       </a>