Added article to the VM landing page

Author: TomArcherMsft

articles/virtual-machines/index.yml

@@ -43,6 +43,8 @@ landingContent:
             url: ./linux/quick-create-portal.md
           - text: Azure PowerShell
             url: ./linux/quick-create-powershell.md
+          - text: Terraform
+            url: ./linux/quick-create-terraform.md
 
   # Card (optional)
   - title: Windows quickstarts