[Request][ESS] Expand requirements for Osquery actions (#4663)

(cherry picked from commit 8ba39b4)

docs/osquery/osquery-response-action.asciidoc

@@ -11,6 +11,7 @@ Osquery Response Actions allow you to add live queries to custom query rules so
 * The {kibana-ref}/manage-osquery-integration.html[Osquery manager integration] must be installed.
 * {agent}'s {fleet-guide}/monitor-elastic-agent.html[status] must be `Healthy`. Refer to {fleet-guide}/fleet-troubleshooting.html[{fleet} Troubleshooting] if it isn't.
 * Your role must have {kibana-ref}/osquery.html[Osquery feature privileges].
+* You can only add Osquery Response Actions to custom query rules.
 --
 
 [role="screenshot"]