Add image variant

Signed-off-by: Nikolaos Karaolidis <nick@karaolidis.com>

assets/js/common/tabs.js

@@ -1,5 +1,7 @@
 function tabsInNewPage() {
-  var links = document.getElementsByTagName("article")[0].querySelectorAll('a');
+  var links = document.getElementsByTagName("article");
+  if (links.length === 0) return;
+  links = links[0].querySelectorAll('a');
   var a = new RegExp('/' + window.location.host + '/');
   links.forEach(link => !a.test(link.href) && link.setAttribute("target", "_blank"));
 }