Developed comprehensive user documentation for the open-energy-transition/pypsa-earth repository, focusing on integrating custom data to support localized scenario development. The work detailed supported data types, YAML configuration options, and required file structures, providing clear guidance for seamless data integration. Using RST for technical writing, the documentation emphasized reproducibility and maintainability, outlining best practices and workflows to streamline onboarding for new users and researchers. By anchoring the documentation to specific repository commits and issues, the approach ensured traceability and alignment with project governance. This contribution strengthened cross-team knowledge transfer and established a foundation for scalable, version-controlled documentation within the project.