Add container security alerts RN

Author: bmansheim

articles/defender-for-cloud/release-notes.md

@@ -21,6 +21,7 @@ To learn about *planned* changes that are coming soon to Defender for Cloud, see
 Updates in November include:
 
 - [Protect containers in your entire GKE organization with Defender for Containers](#protect-containers-in-your-entire-gke-organization-with-defender-for-containers)
+- [Validate Defender for Containers protections with sample alerts](#validate-defender-for-containers-protections-with-sample-alerts)
 
 ### Protect containers in your entire GKE organization with Defender for Containers
 
@@ -30,6 +31,12 @@ Now you can enable Defender for Containers for your GCP organization to protect
 
 Learn more about [connecting GCP projects and organizations](quickstart-onboard-gcp.md#connect-your-gcp-project) to Defender for Cloud.
 
+### Validate Defender for Containers protections with sample alerts
+
+You can now create sample alerts also for Defender for Containers plan. The new sample alerts are presented as being from AKS, Arc-connected clusters, EKS, and GKE resources with different severities and MITRE tactics. You can use the sample alerts to validate security alert configurations, such as SIEM integrations, workflow automation, and email notifications.
+
+Learn more about [alert validation](alert-validation.md).
+
 ## October 2022
 
 Updates in October include: