Fix categories (fixes #5689) (#5736)

* Fix categories (fixes #5689)

* Reset to default sort

* Remove colon

source/_includes/asides/categories.html

@@ -1,7 +1,7 @@
 <section class="aside-module grid__item one-whole lap-one-half">
   <h1 class="title delta">Categories</h1>
   <ul class="divided">
-    {% assign categories = site.categories | sort_natural %}
+    {% assign categories = site.categories | sort %}
     {% for category in categories %}
       <li><a href="/blog/categories/{{ category | first | downcase }}/">{{ category | first | replace: '-', ' '}}</a></li>
     {% endfor %}