Spike: Figure out how to optimize RTD search

[sarina]

Right now when I'm searching for pages I often get suboptimal results first (for example, a mention of a feature in the Juniper release notes before the Educator's page with the exact title I queried on.

Figure out if there's a way to optimize search, or maybe prioritize different docs trees over others in the search.

[sarina]

readthedocs/readthedocs.org#12102