Merge pull request #298512 from ggailey777/patch-11

[Functions] Return the .NET isolated article to the TOC

Author: JamesJBarnett

articles/azure-functions/TOC.yml

@@ -759,6 +759,8 @@
           displayName: upgrade, migrate, language stack
         - name: Migrate Node.js to model v4.x
           href: functions-node-upgrade-v4.md
+    - name: Migrate .NET apps to the isolated model
+      href: migrate-dotnet-to-isolated-model.md
     - name: Move resources
       items:
         - name: Move between subscriptions