nixos-generate-config: Include extraGroups "wheel"

[devhell]

Motivation for this change

I've been asked, on numerous occasions, by my students and others, how
to 'sudo' on NixOS.

Of course new users could read up in the manual on how to do that, or we
could make it more accessible for them by simply making it visible in
the default configuration.nix file.

Things done

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nox --run "nox-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Assured whether relevant documentation is up to date
• Fits CONTRIBUTING.md.

---

[danbst]

It doesn't sound good to allow guest user sudo access xD. Maybe rename example user (anything except root and guest)?

[grahamc]

Nice catch, @danbst.

[devhell]

Sooooo, what name shall we use instead? Off the top of my head maybe alice?

[infinisil]

How about john (from John Doe)

Edit: Or the female version jane (I like jane better). But alice would be fine too, feel free to choose yourself :)

[devhell]

Good auggestion. I think janedoe is my preference, since it might be more recognizable to those who aren't acquainted with 'alice'. I'll update the PR soon. Thanks!

[devhell]

I've updated the PR. :)

[infinisil]

Oh, I thought just jane, janedoe is a bit weird as a username

[devhell]

Duh! @infinisil you're quite right. I brainfarted there, sorry. Updated.

[grahamc]

Great PR :)

[devhell]

Thanks @grahamc, you're very kind. :)