Redmine-operator docs - OCI image

The OCI image used in the redmine-operator charm is the official redmine image from Docker Hub directly, and is uploaded as a resource via Charmub.

Currently, the charm uses image 4.2, which is the latest version available from Docker Hub at the time of writing.

This page will provide a mapping of image version to charm revision for reference as needed:

Charm revision OCI Image revision
all versions 4.2