Adds 404 page.

404.md

@@ -0,0 +1,12 @@
+---
+layout: layouts/home.njk
+permalink: 404.html
+---
+# Content not found.
+
+{% comment %}
+This will work for both GitHub pages and Netlify:
+
+* https://help.github.com/articles/creating-a-custom-404-page-for-your-github-pages-site/
+* https://www.netlify.com/docs/redirects/#custom-404
+{% endcomment %}

index.njk

@@ -4,7 +4,5 @@ tags:
   - nav
 navtitle: Home
 ---
-
 {% set postslist = collections.posts %}
 {% include "postslist.njk" %}
-