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/_data/comments/layout-comments/comment-1470944006665.yml

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+message: "![Bill Murray](http://www.fillmurray.com/400/300)\r\n\r\n“It's hard to be an artist. It's hard to be anything. It's hard to be.”"
+name: Bill Murray
+email: b0caa2a71f5066b3d90711c224578c21
+url: ''
+hidden: ''
+date: '2016-08-11T19:33:25.928Z'

docs/_data/comments/layout-comments/comment-1470944162041.yml

@@ -0,0 +1,6 @@
+message: "> “I never had seen Seinfeld, and they said, ‘Oh, it’s the last episode.’ And I said, ‘Oh, I’ll watch Seinfeld.’ And it was terrible.”\r\n>\r\n> *— From a 2014 interview with Howard Stern*"
+name: Anonymous
+email: 8c7e898f1b570760f834ecc03edf6b35
+url: ''
+hidden: ''
+date: '2016-08-11T19:36:01.033Z'

docs/_data/comments/layout-comments/comment-1472308473018.yml

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+message: test
+name: test
+email: c028c75814332d38e088e43a252b7092
+url: ''
+hidden: ''
+date: '2016-08-27T14:34:32.281Z'