Update 404.md

Author: benjholla

404.md

@@ -1,8 +1,9 @@
 ---
 layout: page
+permalink: /404.html
 title: 404 - Page not found
 ---
 
 Sorry, we can't find that page that you're looking for. You can try take for a look by going [back to the homepage]({{ site.baseurl }}/).
 
-[<img src="{{ site.baseurl }}/images/404.jpg" alt="Constructocat by https://github.com/jasoncostello" style="width: 400px;"/>]({{ site.baseurl }}/)
+[<img src="{{ site.baseurl }}/images/404.jpg" alt="Constructocat by https://github.com/jasoncostello" style="width: 400px;"/>]({{ site.baseurl }}/)