[8.1] [BUG] Document required Security privs for cases (backport #3261)…

… (#3291)

Co-authored-by: Lisa Cawley <lcawley@elastic.co>
Co-authored-by: Nastasha Solomon <79124755+nastasha-solomon@users.noreply.github.com>
Co-authored-by: nastasha.solomon <nastasha.solomon@elastic.co>

docs/getting-started/cases-req.asciidoc

@@ -10,10 +10,10 @@
 You can create roles and define feature privileges at different levels to manage feature access in {kib}. {kib} privileges grant access to features within a specified {kib} space, and you can grant full or partial access. For more information, see
 {kibana-ref}/xpack-spaces.html#spaces-control-user-access[Feature access based on user privileges].
 
-NOTE: To send cases to external systems, you need the
-https://www.elastic.co/subscriptions[appropriate license].
+IMPORTANT: Certain subscriptions and privileges might be required to manage case attachments. For example, to add alerts to cases, you must have privileges for <<enable-detections-ui,managing alerts>>. To send cases to external systems, you need the
+https://www.elastic.co/subscriptions[appropriate license]. 
 
-To grant access to cases, set the {kib} space privileges for the *Cases* and *Actions and Connectors* features as follows:
+To grant access to cases, set the {kib} space privileges for the *Cases* and *{connectors-feature}* features as follows:
 
 [discrete]
 [width="100%",options="header"]