[DOC-12608] Adding note on cosine similarity metric. (#3735)

While I'm in here, Abhi told me they were pulling Windows support for 7.6.4, to return in 8.0.

Author: sarahlwelton

modules/introduction/partials/new_features-76_4.adoc

@@ -30,5 +30,5 @@ curl --get -u <username:password> \
 [#new-features-764-search-service]
 === Search Service
 
-
-* *https://jira.issues.couchbase.com/browse/MB-62634[MB-62634]:* xref:vector-search:vector-search.adoc[Vector Search] is now supported on the Windows platform.
+The Search Service now supports the cosine similarity metric for xref:vector-search:vector-search.adoc[Vector Search indexes].
+For more information about Vector Search similarity metrics, see xref:search:child-field-options-reference.adoc[Child Field Options].