Share a Docker image without using a Docker registry

This is useful for sharing personal Docker images or to import it to a secure environment with no Internet connection.

Example:

# Export Docker image to a .tar file
docker save thingsandcode.com/thingsandcode-web:20220830-pro > /tmp/thingsandcode-web_20220830-pro.tar

# Import .tar file to local Docker installation
docker load --input /tmp/thingsandcode-web_20220830-pro.tar