Update toc.yml

update toc with provisioned reservation update doc add

Author: sydneemayers

articles/ai-services/openai/toc.yml

@@ -91,6 +91,8 @@ items:
       displayName: PTU, provisioned, provisioned throughput units
     - name: Azure OpenAI PTU update
       href: ./concepts/provisioned-migration.md
+    - name: Azure OpenAI PTU reservation update
+      href: ./concepts/provisioned-reservation-update.md
     - name: Legacy models
       href: ./concepts/legacy-models.md
 - name: How-to