Merge branch '388-job_structure-check-gitkeep-shouldn-t-be-mandatory' into 'latest'

Resolve "Job_structure check : ".gitkeep" shouldn't be mandatory"

Closes #388

See merge request r2devops/hub!226

(cherry picked from commit 258d35af)

a3c306a6 Feat: remove optional screenshots folder 🎉
c8a44850 Chore: remove useless .gitkeep
9042f0b3 Fix: correct builder behavior with optional files
4c1f11da Chore: update documentation for optional directory
65990dba Fix python format
525bdb9c Chore: remove concat. in builder.py