iOS 16.4 or later and Webpages in Safari 16

Hi,

Apple hase realsed the [Webpage push notification](https://developer.apple.com/documentation/usernotifications/sending_web_push_notifications_in_web_apps_and_browsers) in iOS 16.4. This library support it? I've try opening the https://pushjs.org demo but doesn't work.

Thanks,
Francesco