Client search widget

[mtorres253]

As an 18F employee, even with a GUI for the handbook, I may still want to just search for a particular thing. There should be a way to do this.

( When #523 is done, we will have search results to get from various endpoints. This story is to just hook up a client side search)

Acceptance Criteria:
As users type into the search box, and as we get results, they appear in a dropdown. When the user clicks on one of the result in the dropdown, the user is taken to that page of the handbook.