conversions were done using https://github.com/pennae/nix-doc-munge
using (probably) rev f34e145 running
nix-doc-munge nixos/**/*.nix
nix-doc-munge --import nixos/**/*.nix
the tool ensures that only changes that could affect the generated
manual *but don't* are committed, other changes require manual review
and are discarded.
Now the default way to define NixOS window manager modules is to use
mkEnableOption to describe the module itself.
In this commit, all files on nixos/modules/services/x11/window-managers
are changed.
