sorting of search results

from Enrique's original ticket #173
> Adding fields: The search bar is a bit weird. Writing "growth medium" does pull up the result, but is way below, being an exact match I would expect for it to be at least the first entry?

# Analysis
If we had used Mongo's text index we could have added weights to certain fields, but since we are using homegrown search we need an alternative.

The issue provides no file, test, or entry point for the search implementation. Start by locating the homegrown search code and its existing result-ordering tests, then clarify the desired ranking behavior and how an exact match should be verified before implementation.

Written by the indexing model from the issue text.