http://username.github.io/pages.html
http://username.github.io/archive.html
http://username.github.io/index.html
http://username.github.io/sitemap.txt
http://username.github.io/rss.xml
http://username.github.io/tags.html
http://username.github.io/atom.xml
http://username.github.io/categories.html
http://username.github.io/lessons/2011/12/29/jekyll-introduction