Merge branch 'docs-aqualls-timer-entitlement' into 'master'

Add entitlement for SLA countdown timer

See merge request gitlab-org/gitlab!45563

doc/operations/incident_management/incidents.md

@@ -181,7 +181,7 @@ un-threaded and ordered chronologically, newest to oldest:
 
 ### Service Level Agreement countdown timer
 
-> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/241663) in GitLab 13.5.
+> [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/241663) in [GitLab Premium](https://about.gitlab.com/pricing/) 13.5.
 
 After enabling **Incident SLA** in the Incident Management configuration, newly-created
 incidents display a SLA (Service Level Agreement) timer showing the time remaining before