[FTS] Add information regarding tooManyClauses limitation

There's a hard bound on the number of term searchers that can be spun off for a query, and the number is at 1024. This is a known limit set by FTS.

For example, say the user initialized a regex search for a*, this could match terms like apple, adam, andrew, alex, etc. If the number of candidate terms generated for a single search is greater than 1024, the query will error out with a tooManyClauses error.

The idea here is for the user to improve their search by making the search parameters a bit more specific, and/or using the right analyzers/tokenizers.