Add a 'stylix.enable' option to enable or disable all Stylix modules in
order to resolve issues similar to [2].
To align with the default 'lib.mkEnableOption' [1] behavior,
'stylix.enable' defaults to 'false'.
BREAKING CHANGE: Stylix is disabled by default. To enable it, use:
stylix.enable = true;
[1]: https://github.com/NixOS/nixpkgs/blob/23.11/lib/options.nix#L91-L105
[2]: https://github.com/danth/stylix/issues/216
Co-authored-by: Daniel Thwaites <danthwaites30@btinternet.com>
Co-authored-by: Jalil David Salamé Messina <jalil.salame@gmail.com>
Co-authored-by: NAHO <90870942+trueNAHO@users.noreply.github.com>
