Add service retirement workbook

Author: ikhapova

articles/advisor/toc.yml

@@ -48,6 +48,8 @@
     href: advisor-security-recommendations.md
   - name: Improve reliability  
     href: advisor-how-to-improve-reliability.md
+  - name: Plan migration of workloads impacted by services retirement
+    href: advisor-how-to-plan-migration-workloads-service-retirement.md
   - name: Improve the performance of highly used VMs
     href: advisor-how-to-performance-resize-high-usage-vm-recommendations.md
   - name: Use tags to filter recommendations and score