Remove our categorization hack, and add category view pages instead.

_layouts/category_index.html

@@ -0,0 +1,14 @@
+---
+layout: default
+---
+<article class="post">
+
+  <header class="post-header">
+    <h1 class="post-title">{{ page.title }}</h1>
+  </header>
+
+  <div class="post-content">
+    {% include category_list.html category=page.data['category'] limit=0 %}
+  </div>
+
+</article>