Hardy

Great plugin, thank you for your efforts! One feature request i have would be to be able to group updates of certain containers. I managed to corrupt my Nextcloud installation because i shutdown the database (because of an update) one time. Since then i stop Nextcloud before updating the database container. I could stop them all together with your plugin already, but the Nextcloud instance takes some time and the rest could stay up meanwhile. So if we could make a backup group and shut them down in a certain order and start them together the plugin would be perfect for me. Thank you again