Motivation for this change

Profiles lack discovery and documentation. Hopefully this is the beginning of a fix. Clone-config is empty because I haven't had the time to understand what it does, so someone should provide at least a short summary.

In fact, I'd like to have insight on why most options are set in each profile, I just resorted to state what is set, without a reason why.

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)
• Fits CONTRIBUTING.md.