move blog to /blog

categories.html

@@ -1,13 +0,0 @@
----
-layout: page
-title: Posts by categories
-permalink: /categories/
----
-{% for category in site.categories %}
-<h3>{{ category[0] }}</h3>
-    <ul>
-            {% for post in category[1] %}
-                <li><a href="{{ site.baseurl }}{{ post.url }}">{{ post.title }}</a></li>
-            {% endfor %}
-    </ul>
-{% endfor %}