* modules/rosenthal/home/services/emacs.scm (<home-emacs-configuration>): New
data type.
(home-emacs-package): New procedure.
(home-emacs-shepherd, home-emacs-service-type): New variables.
* modules/rosenthal/home/services/gtk.scm
(home-gtk2-xdg-configuration-files)
(home-gtk3-xdg-configuration-files
(home-gtk4-xdg-configuration-files): New procedures.
(home-gtk2-environment-variables)
(home-gtk2-service-type)
(home-gtk3-service-type)
(home-gtk4-service-type): New variables.
* modules/rosenthal/services/desktop.scm
(home-theme-gtk2, home-theme-gtk3): New procedures.
(%home-theme-xdg-config): Delete procedure.
(home-theme-service-type) [extensions]:
Replace home-xdg-configuration-files-service-type to these new services.
