ADE - extensibility model - added links to landing page

Author: RoseHJM

articles/deployment-environments/index.yml

@@ -60,8 +60,14 @@ landingContent:
     linkLists:
       - linkListType: how-to-guide
         links:
-          - text: Configure container image to execute deployments
-            url: how-to-configure-extensibility-model-custom-image.md
+          - text: What is the ADE Extensibility Model?
+            url: concept-extensibility-model.md
+          - text: Create an ARM or Bicep custom image
+            url: /azure/deployment-environments/how-to-configure-extensibility-model-custom-image?tabs=sample%2Cprivate-registry&pivots=arm-bicep
+          - text: Create a Terraform custom image
+            url: /azure/deployment-environments/how-to-configure-extensibility-model-custom-image?tabs=custom-script%2Cprivate-registry&pivots=terraform#use-a-standard-container-image
+          - text: Create a Pulumi custom image
+            url: /azure/deployment-environments/how-to-configure-extensibility-model-custom-image?tabs=sample%2Cprivate-registry&pivots=pulumi#use-a-standard-container-image
           - text: Troubleshoot custom image errors and warnings
             url: troubleshoot-custom-image-logs-errors.md