Update openshift docs

[tomach]

Summary of changes

This updates the OpenShift documentation to reflect that the crate-control sidecar image is automatically published to Docker Hub as part of the release pipeline. It is no longer required that users must build and publish the image themselves.

Checklist

• Link to issue this PR refers to:
• Relevant changes are reflected in CHANGES.rst
• Added or changed code is covered by tests
• Documentation has been updated if necessary
• Changed code does not contain any breaking changes (or this is a major version change)

[plaharanne]

👍