Bulk - EDP fix broken links (app gateway toc)

Fix broken link per work item https://dev.azure.com/msft-skilling/Content/_workitems/edit/436781.

Author: v-thepet

articles/application-gateway/toc.yml

@@ -12,7 +12,7 @@
   - name: Architecture best practices for Azure Application Gateway v2
     href: /azure/well-architected/service-guides/azure-application-gateway?toc=/azure/application-gateway/toc.json&bc=/azure/application-gateway/breadcrumb/toc.json
   - name: What is load balancing and content delivery?
-    href: /azure/networking/load-balancer-content-delivery/load-balancing-content-delivery-overview.md
+    href: /azure/networking/load-balancer-content-delivery/load-balancing-content-delivery-overview
   - name: Choose a load balancing solution
     href: /azure/architecture/guide/technology-choices/load-balancing-overview?toc=/azure/load-balancer/toc.json
   - name: Create Application Gateway - Portal