ADE- manage environment - added parameters section

Author: RoseHJM

articles/deployment-environments/configure-catalog-item.md

@@ -86,6 +86,53 @@ To add a catalog item:
 
 The service scans the repository to find new catalog items. After you sync the repository, new catalog items are available to all projects in the dev center.
 
+### Specify parameters for a catalog item
+
+Catalog items can use parameters to allow developers to customize their environments. Parameters  are specified in the manifest.yaml file. You can define a default value for a parameter that the developer creating the environment can overwrite. The following script shows two parameters; `location` and `name`. Location has a default value of `[resourceGroup().location]`, which sets the location of the environment to the location of the resource group.
+
+```yml
+name: WebApp
+summary: Azure Web App Environment
+description: Deploys a web app in Azure without a datastore
+runner: ARM
+templatePath: azuredeploy.json
+parameters:
+- id: "location"
+  name: "location"
+  description: "Location to deploy the environment resources"
+  default: "[resourceGroup().location]"
+  type: "string"
+- id: "name"
+  name: "name"
+  description: "Name of the Web App "
+  default: ""
+  type: "string"
+  required: false
+
+  required: false
+```
+
+Developers can supply values for specific parameters for their environments through the developer portal.
+
+:::image type="content" source="media/configure-catalog-item/parameters.png" alt-text="Screenshot showing the parameters pane.":::
+
+Developers can also supply values for specific parameters for their environments through the CLI.
+
+```azurecli
+az devcenter dev environment create --catalog-item-name
+                                    --catalog-name
+                                    --dev-center
+                                    --environment-name
+                                    --environment-type
+                                    --project
+                                    [--description]
+                                    [--no-wait]
+                                    [--parameters]
+                                    [--tags]
+                                    [--user]
+                                    [--user-id]
+```
+Refer to the [Azure CLI devcenter extension](/cli/azure/devcenter/dev/environment?view=azure-cli-latest) for full details.
 ## Update a catalog item
 
 To modify the configuration of Azure resources in an existing catalog item, update the associated ARM template JSON file in the repository. The change is immediately reflected when you create a new environment by using the specific catalog item. The update also is applied when you redeploy an environment that's associated with that catalog item.