The script uses the package [`libguestfs-tools`](https://libguestfs.org)' `virt-builder` to download and customize a Debian image. and then add it as a template to Proxmox.
The script expects `authorized_keys` to be in the current directory. Copy the correct contents from the [appropriate repository](https://gitlab.hamburg.ccc.de/ccchh/infrastructure-authorized-keys).
Please use "Full Clone" when creating a VM based on this template. Using Linked Clone means that the template's disk cannot be recreated since the linked clones need it. This means that the script cannot update the template.