Revert "[ACI] article: deploy to vnet"

This reverts commit 57dfd2f.

Author: mmacy

articles/container-instances/TOC.yml

@@ -45,8 +45,6 @@
       href: container-instances-multi-container-group.md
     - name: Deploy from Azure Container Registry
       href: container-instances-using-azure-container-registry.md
-    - name: Deploy to Azure Virtual Network
-      href: container-instances-vnet.md
     - name: Set environment variables (env)
       href: container-instances-environment-variables.md
     - name: Configure liveness probes