This uses the hanna command shipped with the hanna gem. The
preferred method of using is to require 'hanna/rdoctask' in
your Rakefile but this caused various gem depency errors (blame
Hoe, rdoc 2.0, Echoe, and rubyforge).
You have to install mislav's hanna gem from github:
$ sudo gem install mislav-hanna --source=http://gems.github.com
Run the doc task to generate rdoc under doc/api:
$ rake doc
See mislav's repo for more info on template usage:
http://github.com/mislav/hanna
See the HAML docs for an example of the hanna template in action:
http://haml.hamptoncatlin.com/docs/rdoc