Marie Catillon contributed to the EPF-MDE/git-first-steps repository by enhancing contributor onboarding and repository metadata management. She updated the AUTHORS file to include a new contributor, Marie79418, and created a placeholder file to improve attribution accuracy and visibility within the project. Her work focused on documentation and file management, using text-based workflows to ensure clarity and maintainability. By resolving merge conflict markers in the AUTHORS file, Marie reduced potential confusion and friction for future pull requests. The changes were implemented through a concise set of disciplined commits, reflecting a careful approach to repository hygiene and contributor experience within the project.