Add documentation for query rules retriever (elastic#115696) (elastic#116401)

Author: leemthompo

docs/reference/query-dsl/rule-query.asciidoc

@@ -12,6 +12,12 @@
 The old syntax using `rule_query` and `ruleset_id` is deprecated and will be removed in a future release, so it is strongly advised to migrate existing rule queries to the new API structure.
 ====
 
+[TIP]
+====
+The rule query is not supported for use alongside reranking.
+If you want to use query rules in conjunction with reranking, use the <<rule-retriever, rule retriever>> instead.
+====
+
 Applies <<query-rules-apis,query rules>> to the query before returning results.
 Query rules can be used to promote documents in the manner of a <<query-dsl-pinned-query>> based on matching defined rules, or to identify specific documents to exclude from a contextual result set.
 If no matching query rules are defined, the "organic" matches for the query are returned.