Sim Ji Young established foundational documentation for the Vacation feature in the dasfasdfsddss/github-demo repository, focusing on creating clear and accessible Markdown files to support ongoing and future development. Their work involved drafting an initial guidance document, 방학 방학.md, and setting up documentation scaffolding to streamline onboarding and team collaboration. Sim Ji Young prioritized documentation integrity by reverting an unstable Readme update, ensuring that user-facing content remained reliable. Throughout the process, they maintained a clean Git history with explicit commit messages, demonstrating attention to traceability and maintainability. The work emphasized documentation skills and proficiency with Markdown and version control.