Use post excerpts on main blog page instead of full posts
Add blog subdirectory (so that we can have a main page and a connected
blog)
Add basic category and tag parsing functionality from minddust.com (partially described at http://www.minddust.com/post/tags-and-categories-on-github-pages/)
Add shell script and Rakefile task that will sync categories and tags
used in current posts to the appropriate pages, to the YAML data files,
 and to the index