* gnu/services/web.scm (<gmnisrv-configuration>): New record type.
(%default-gmnisrv-config-file): New variable.
(%gmnisrv-accounts, %gmnisrv-activation): New variables.
(gmnisrv-shepherd-service): New procedure.
(gmnisrv-service-type): New variable.
* doc/guix.texi (Web Services): Document it.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>