[dev] Simplified input format for PDUs

.../grid5000/sites/nancy/clusters/graoully/graoully_pdu.yaml

...id5000/sites/nancy/clusters/graphene/graphene_manual.yaml

...id5000/sites/nancy/clusters/graphite/graphite_manual.yaml

...grid5000/sites/nancy/clusters/griffon/griffon_manual.yaml

...id5000/sites/nancy/clusters/grimoire/grimoire_manual.yaml

...t/grid5000/sites/nancy/clusters/grisou/grisou_manual.yaml

...t/grid5000/sites/reims/clusters/stremi/stremi_manual.yaml

...d5000/sites/rennes/clusters/parapide/parapide_manual.yaml

...000/sites/rennes/clusters/parapluie/parapluie_manual.yaml

...d5000/sites/rennes/clusters/parasilo/parasilo_manual.yaml

...000/sites/rennes/clusters/paravance/paravance_manual.yaml

dev/reference-api/reference-api.rb