Query Autocomplete (also known as "typeahead") lets the Search Appliance
suggest full words from the user's partially typed queries as they're being
typed. If the user has typed ense, query autocomplete may suggest
ensemble, enseignement, etc.
Like Spell Check, the list of words used for Query Autocomplete comes
from the current profile's content, so the only suggestions made will be words
that occur somewhere in the content.
Query Autocomplete is ordered with a priority system, where words that occur
more often are ranked higher, and words that occur in titles are ranked much
higher.