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

docs/_includes/comments-providers/scripts.html

@@ -0,0 +1,18 @@
+{% if site.comments.provider and page.comments %}
+
+{% case site.comments.provider %}
+{% when "disqus" %}
+  {% include /comments-providers/disqus.html %}
+{% when "discourse" %}
+  {% include /comments-providers/discourse.html %}
+{% when "facebook" %}
+  {% include /comments-providers/facebook.html %}
+{% when "google-plus" %}
+  {% include /comments-providers/google-plus.html %}
+{% when "staticman" %}
+  {% include /comments-providers/staticman.html %}
+{% when "custom" %}
+  {% include /comments-providers/custom.html %}
+{% endcase %}
+
+{% endif %}