these changes were generated with nixq 0.0.2, by running
nixq ">> lib.mdDoc[remove] Argument[keep]" --batchmode nixos/**.nix
nixq ">> mdDoc[remove] Argument[keep]" --batchmode nixos/**.nix
nixq ">> Inherit >> mdDoc[remove]" --batchmode nixos/**.nix
two mentions of the mdDoc function remain in nixos/, both of which
are inside of comments.
Since lib.mdDoc is already defined as just id, this commit is a no-op as
far as Nix (and the built manual) is concerned.
Some settings which where before inside the xserver module, are generic
and also required for SDDM under wayland. To make them easily re-usable
lets extract them.
