Add `highlight RTF` function & docs
[git] Add `search` feature for history search
[zsh] Enable `emacs` plugin

Yes, it's true.
[zsh] Add `ducks` alias

This alias allows us to check disk usage more easily with a sorted list.
[zsh] Add `spy` function

Identify and search for active network connections easily.

@see http://alias.sh/identify-and-search-active-network-connections
[iterm] Update settings