Add categories page

_config.yml

@@ -48,6 +48,8 @@ links:
     url: /archive
   - title: Contact
     url: /contact
+  - title: Categories
+    url: /categories
 
 # Build settings
 

categories.html

@@ -0,0 +1,20 @@
+---
+layout: page
+title: "Categories"
+---
+
+{% for tag in site.categories %}
+  <span id="{{ tag[0] | slugify }}">{{ tag[0] | capitalize }}</span>
+  <ul>
+    {% assign pages_list = tag[1] %}
+    {% for post in pages_list reversed %}
+      {% if post.title != null %}
+      {% if group == null or group == post.group %}
+      <li><a href="{{ site.baseurl }}{{ post.url }}">{{ post.title }}, <span ><time>{{ post.date | date: site.date_format }}</time></a></li>
+      {% endif %}
+      {% endif %}
+    {% endfor %}
+    {% assign pages_list = nil %}
+    {% assign group = nil %}
+  </ul>
+{% endfor %}