footer: remove trailing slashes from links

trailing slashes result in 404 for GitHub Pages when
an extensionless path is used with uglyURLs enabled

Author: ritorhymes

layouts/partials/footer.html

@@ -3,8 +3,8 @@
   <nav>
     <ul>
       <li><a href="{{ relURL "/" }}">Home</a></li>
-      <li><a href="{{ relURL "architecture/" }}">Architecture</a></li>
-      <li><a href="{{ relURL "reply-to-this/" }}">Reply to this</a></li>
+      <li><a href="{{ relURL "/architecture" }}">Architecture</a></li>
+      <li><a href="{{ relURL "/reply-to-this" }}">Reply to this</a></li>
     </ul>
   </nav>
   <a class="footer-home-link" href="{{ relURL "/" }}" aria-label="Home">