add to ToC

Author: dlepow

articles/api-management/TOC.yml

@@ -108,6 +108,8 @@
               href: configure-custom-domain.md
             - name: Deploy to multiple Azure regions
               href: api-management-howto-deploy-multi-region.md
+            - name: Configure Front Door
+              href: front-door-api-management.md
             - name: Enable zone redundancy
               displayName: Availability zones
               href: ../availability-zones/migrate-api-mgt.md?toc=%2Fazure%2Fapi-management%2Ftoc.json&bc=/azure/api-management/breadcrumb/toc.json