self-signed-certificates Tracks and Compatibility

This document seeks to clarify which track should be used when deploying a new self-signed-certificates charm.

The names of the tracks can be confusing.

• The latest track is actually a legacy track that should no longer be used where possible. Charms should migrate to the 1/stable track when possible.
  • It is not compatible with requirer charms using V4 of the tls-certificates library and APP mode.
• The 1 track is the current track and should be used for all new deployments.

The charm is able to run on any cloud and substrate that Juju supports, be it a k8s container or a VM.