New reconfigure, creating a file under /etc

[SuarezMiguelC]

Hello help guix!, I'm trying to make a reconfigure, where I create a file under 
/etc.

This because, since I'm using gnome as my desktop environment, I want to add 
some functionalities on it to be more 'connected' to GuixSD, especifically, 
create the file 'os-release' with the content 'PRETTY_NAME=Guix-System"', this 
will make gnome to identify the system and display it on settings, thus a 
better natural 'connection' between gnome and guix.

Using 'etc-service-type' on my new reconfigure, it looks like this:

  (services
    (append
     (list (service gnome-desktop-service-type)
   (service etc-service-type
    (list `("os-release" ,(plain-file "os-release"
      "PRETTY_NAME=Guix-System"))))
   (set-xorg-configuration
    (xorg-configuration
     (keyboard-layout keyboard-layout))))
     %desktop-services)))

Trying to run this reconfigure will cause an error for 'more than one etc 
service', so I guess I don't have the correct syntax, I've on the IRC chat, but 
no response, because of this, I write an e-mail.

Thanks in advantage!