Add screenshot and more details

source/_components/persistent_notification.markdown

@@ -14,4 +14,41 @@ ha_release: 0.23
 
 The `persistant_notification` can be used to show a message on the frontend that has to be dismissed by the user.
 
-The service `persistent_notification/create`. Takes in `message`, `title`, and `notification_id`. If `notification_id` is given, it will overwrite the notification if there already was a notification with that id.
+<p class='img'>
+  <img src='/images/screenshots/persistant-notification.png' />
+</p>
+
+### {% linkable_title Service %}
+
+The service `persistent_notification/create` takes in `message`, `title`, and `notification_id`.
+
+| Service data attribute | Optional | Description |
+| ---------------------- | -------- | ----------- |
+| `message`              |       no | Body of the notification.
+| `title`                |      yes | Title of the notification.
+| `notification_id`      |      yes | If `notification_id` is given, it will overwrite the notification if there already was a notification with that ID.
+
+The `persistant_notification` component supports specifying [templates](/topics/templating/) for both the `message` and the `title`. This will allow you to use the current state of Home Assistant in your notifications.
+
+In an [action](https://home-assistant.io/getting-started/automation-action/) of your [automation setup](/getting-started/automation/) it could look like this with a customized subject.
+
+```yaml
+action:
+  service: persistant_notification.create
+  data:
+    message: "Your message goes here"
+    title: "Custom subject"
+```
+
+### {% linkable_title Create a perstistant notification %}
+
+Use **Call Service** from the **Developer Tools** to call the `persistant_notification` service. Choose `persistant_notification/create` from the list of **Available services:** and enter something like the sample below into the **Service Data** field and hit **CALL SERVICE**.
+
+```json
+{
+  "notification_id": "1234",
+  "title": "Sample notification",
+  "message": "This is a sample text"
+}
+```
+This will create the notification entry shown above.