Plugin help request: Add support for Reminders to Event Helpers

[jgclark]

Aim: extend existing Event Helpers plugin to cover Reminders as well. I left that as an exercise for someone else, as I don't use Apple reminders. I think it should be pretty easy to do, as the reminders are available as part of the same API calls that already get and process events.

The name of the plugin might need to change as a result ... but that's a detail that can be worked out in due course.