Use in your own damned printer

[camelpunch]

Although I've installed it, I haven't used my printer in anger with a Klix installation, with updates etc.

This is a first step towards getting user feedback. The next will be beta testers.

[camelpunch]

Issues:

• need to use tar -xz to decompress the streamed gzipped response from the server
• need to either say nixos-rebuild switch --flake .#default or revert to include the hostname in the flake (because nixos-rebuild doesn't default to default)
• rebuild fails because it's waiting for a (presumably wired) network connection