Update TOC to move Prescaling section

Move 'Prescaling' section to Configure section.

Author: duongau

articles/firewall/toc.yml

@@ -164,6 +164,8 @@ items:
       href: dns-details.md
     - name: DNS proxy settings
       href: dns-settings.md
+  - name: Prescaling
+    href: prescaling.md
   - name: Tags
     items:
     - name: FQDN tags
@@ -210,8 +212,6 @@ items:
     href: /azure/developer/terraform/firewall-upgrade-premium?toc=/azure/firewall/toc.json&bc=/azure/firewall/breadcrumb/toc.json
 - name: Operational excellence
   items:
-  - name: Prescaling
-    href: prescaling.md
   - name: Monitoring
     items:
     - name: Logs and metrics