Autofocus

Autofocus the search whenever a key is pressed (besides ctrl/alt/meta + key)

May want to consider only doing this when the search is in the viewport? I personally prefer it like this however. (code is stolen from one of my old projects)
`var $ = jQuery;` can be removed, `var $document = $(window.document)` needs to be inside the function - otherwise it would throw on node since there's no `window`