Mount a directory for restore testing

And for actual restores, should the time come...

ansible/roles/intersect-docker/files/duplicati/docker-compose.yml

@@ -9,7 +9,7 @@ services:
       - TZ=Europe/London
     volumes:
       - ./config:/config
-      - ./backups:/backups
+      - ./restore:/restore
       - /srv/nextcloud-data/data/:/source/nextcloud:ro
       - /opt/gitea/repos/repositories:/source/repositories:ro
       - /scratch/db-backups:/source/db-backups:ro