[log] Add file hierarchy for hardware intervention logs

...es/luxembourg/clusters/petitprince/nodes/petitprince-9.md

log/grid5000/sites/lyon/clusters/gemini/nodes/gemini-1.md

log/grid5000/sites/lyon/clusters/gemini/nodes/gemini-2.md

log/grid5000/sites/lyon/clusters/hercule/nodes/hercule-1.md

log/grid5000/sites/lyon/clusters/hercule/nodes/hercule-2.md

log/grid5000/sites/lyon/clusters/hercule/nodes/hercule-3.md

log/grid5000/sites/lyon/clusters/hercule/nodes/hercule-4.md

log/grid5000/sites/lyon/clusters/neowise/nodes/neowise-1.md

log/grid5000/sites/lyon/clusters/neowise/nodes/neowise-10.md

log/grid5000/sites/lyon/clusters/neowise/nodes/neowise-2.md

log/grid5000/sites/lyon/clusters/neowise/nodes/neowise-3.md

log/grid5000/sites/lyon/clusters/neowise/nodes/neowise-4.md

log/grid5000/sites/lyon/clusters/neowise/nodes/neowise-5.md

log/grid5000/sites/lyon/clusters/neowise/nodes/neowise-6.md

log/grid5000/sites/lyon/clusters/neowise/nodes/neowise-7.md

log/grid5000/sites/lyon/clusters/neowise/nodes/neowise-8.md

log/grid5000/sites/lyon/clusters/neowise/nodes/neowise-9.md

log/grid5000/sites/lyon/clusters/nova/nodes/nova-1.md

log/grid5000/sites/lyon/clusters/nova/nodes/nova-10.md

log/grid5000/sites/lyon/clusters/nova/nodes/nova-11.md