Updating TOC

add the performance page.

Author: JeffreyWolford

articles/azure-monitor/toc.yml

@@ -231,6 +231,9 @@ items:
         href: agents/azure-monitor-agent-migration.md
       - name: Migration tools
         href: agents/azure-monitor-agent-migration-tools.md
+    - name: Performance
+      displayName: Performance
+      href: /azure/azure-monitor/agents/azure-monitor-agent-performance.md
     - name: FAQ
       displayName: Azure Monitor agent FAQ
       href: /azure/azure-monitor/faq#azure-monitor-agent