Add vim-yardoc vim plugin

This plugin provides Ruby syntax extensions for highlighting YARD
documentation. In contrast with vim-yard, vim-yardoc piggy backs on
Vim's existing Ruby syntax to provide an integrated experience.

More information:

  https://github.com/noprompt/vim-yardoc
Add .hamljs to .ackrc
Teach ack to use color

This will make acking a nicer, happier experience.
Turn off pager for git status

Using a pager here takes me out of my flow.