Bug: missing step in tutorial, in notification click

[antonypenn]

It says:
Try it out
Try triggering a push message in DevTools again and click on the notification. You'll now see the notification close and open a new tab.

However, you have just made a change to the sw.js service worker, so the index.html page needs to be refreshed to load this, before you can send a notification and see a popup window. Thanks.