* gnu/services/syncthing.scm: (syncthing-config-file, syncthing-folder,
syncthing-device, syncthing-folder-device): New records.
(syncthing-service-type): Add special-files-service-type extension for
the config file.
(syncthing-files-service): Add service to create config file.
* gnu/home/services/syncthing.scm: (home-syncthing-service-type):
Extend home-files-services-type and re-exported more things from
gnu/services/syncthing.scm.
* doc/guix.texi: (syncthing-service-type): Document changes.
Change-Id: I87eeba1ee1fdada8f29c2ee881fbc6bc4113dde9
Signed-off-by: Leo Famulari <leo@famulari.name>