Move gh-pages branch files into /docs and add test files

- Jekyll ignore `/docs` and `/test` folders when using from root
- Update Staticman config to point to correct branch and data file location
- Replace `{{ base_path }}` references with `absolute_url` filter
- Update documentation

test/_pages/sitemap.md

@@ -0,0 +1,37 @@
+---
+layout: archive
+title: "Sitemap"
+permalink: /sitemap/
+author_profile: false
+---
+
+{% include base_path %}
+
+A list of all the posts and pages found on the site. For you robots out there is an [XML version]({{ base_path }}/sitemap.xml) available for digesting as well.
+
+<h2>Pages</h2>
+{% for post in site.pages %}
+  {% include archive-single.html %}
+{% endfor %}
+
+<h2>Posts</h2>
+{% for post in site.posts %}
+  {% include archive-single.html %}
+{% endfor %}
+
+{% capture written_label %}'None'{% endcapture %}
+
+{% for collection in site.collections %}
+{% unless collection.output == false or collection.label == "posts" %}
+  {% capture label %}{{ collection.label }}{% endcapture %}
+  {% if label != written_label %}
+  <h2>{{ label }}</h2>
+  {% capture written_label %}{{ label }}{% endcapture %}
+  {% endif %}
+{% endunless %}
+{% for post in collection.docs %}
+  {% unless collection.output == false or collection.label == "posts" %}
+  {% include archive-single.html %}
+  {% endunless %}
+{% endfor %}
+{% endfor %}