Include images versions in backup

[jgwehr]

Describe the solution you'd like
When backing up the docker config, export each image's version to facilitate "picture perfect" recovery. It's possible that a given backup is not backwards-compatible with the :latest tag at time of recovery.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.

• Update README.md
• Added to backup.sh