Added example based on event platform (#6435)

* Added example based on event platform

Persistent notification automation example based on event platform

* Minor changes

source/_components/persistent_notification.markdown

@@ -56,6 +56,29 @@ action:
     notification_id: "1234"
 ```
 
+This automation example shows a notification when the Z-Wave network is starting and removes it when the network is ready.
+
+```yaml
+- alias: 'Z-Wave network is starting'
+  trigger:
+    - platform: event
+      event_type: zwave.network_start
+  action:
+    - service: persistent_notification.create
+      data:
+        title: "Z-Wave"
+        message: "Z-Wave network is starting..."
+        notification_id: zwave
+
+- alias: 'Z-Wave network is ready'
+  trigger:
+    - platform: event
+      event_type: zwave.network_ready
+  action:
+    - service: persistent_notification.dismiss
+      data:
+        notification_id: zwave
+```
 
 ### {% linkable_title Markdown support %}