Today CDEvents only supports one event, artifact.published, which is meant to be produced by artifact repositories.
Repositories usually support more kind of events, for events like artifact.pulled, artifact.deleted and artifact.scanned, see the Harbor docs for an example.
We should consider extending the data model to include such events.
Design doc: https://hackmd.io/AfT-5D3JQZynKk5yDyAWeA