ft:search(
query,opts) ->results
Search for documents matching a query
Returns an array of {key, score} tables ranked by BM25 score (descending).
Options: top_k (max results; default 10), k1 (BM25 k1; default 1.2),
b (BM25 b; default 0.75). The query is analyzed with the same analyzer
used to index the documents.