Worked on documentation maintenance for the coscene-io/docs repository, focusing on improving clarity and maintainability. The primary contribution involved removing an empty placeholder file, 3-add-rule.md, from the docs/use-case/data-diagnosis/ directory to streamline the documentation structure and reduce potential confusion for users. This update did not introduce any code changes, ensuring the functional integrity of the project remained intact. The work emphasized careful repository hygiene and traceability, with changes recorded through a clear Git commit. Utilized skills in Markdown and Git version control, demonstrating attention to detail in documentation workflows and a methodical approach to repository organization and maintenance.