added to the TOC

Author: spelluru

articles/lab-services/TOC.yml

@@ -152,6 +152,8 @@
       href: deploy-nested-template-environments.md
     - name: Use Azure managed identities to deploy environments
       href: use-managed-identities-environments.md
+    - name: Security alerts for environments
+      href: environment-security-alerts.md
   - name: Manage reusable templates
     items: 
     - name: Custom images vs. formulas