FEATURE: Webhook events list

[mountainash]

It would be really helpful to know all the different Cockpit events that can be used to trigger a webhook, and not just the names of the event, but also what actions lead to them triggering.

Currently https://getcockpit.com/documentation/pro/webhooks/introduction isn't detailed enough to be that helpful.

It would be cool if the Create Webhook screen in Cockpit Settings showed all the hooks available for an instance (inc. Custom Webhooks) with the ability to easily add them to a Webhook

GitHub does this well at their Org level.