* etc/guix-daemon.service.in: New file, provided by Ricardo Wurmus. * daemon.am (CLEANFILES): Add etc/guix-daemon.service. (systemdservicedir, nodist_systemdservice_DATA): New variables. (EXTRA_DIST): Add etc/guix-daemon.service.in. * doc/guix.texi (Binary Installation, Build Environment Setup): Mention 'guix-daemon.service'.