Update group notify component configuration (#7429)

* Update group notify component configuration

* Minor changes

source/_components/notify.group.markdown

@@ -29,9 +29,22 @@ notify:
       - service: html5_nexus
 ```
 
-Configuration variables:
-
-- **name** (*Required*): Setting the parameter `name` sets the name of the group.
-- **services** (*Required*): A list of all the services to be included in the group.
-  - **service** (*Required*): The service part of an entity ID, i.e. if you use `notify.html5` normally, just put `html5`. Note that you must put everything in lower case here. Although you might have capitals written in the actual notification services!
-  - **data** (*Optional*): A dictionary containing parameters to add to all notify payloads. This can be anything that is valid to use in a payload, such as `data`, `message`, `target`, `title`.
+{% configuration %}
+name:
+  description: Setting the parameter `name` sets the name of the group.
+  required: true
+  type: string
+services:
+  description: A list of all the services to be included in the group.
+  required: true
+  type: list
+  keys:
+    service:
+      description: The service part of an entity ID, e.g. if you use `notify.html5` normally, just put `html5`. Note that you must put everything in lower case here. Although you might have capitals written in the actual notification services!
+      required: true
+      type: string
+    data:
+      description: A dictionary containing parameters to add to all notify payloads. This can be anything that is valid to use in a payload, such as `data`, `message`, `target` or `title`.
+      required: false
+      type: string
+{% endconfiguration %}