Generate Markdown Reference Documentation for R Packages // Generates plain Markdown reference documentation for any R package, installed or a local development source tree, optimized for rendering in the 'GitHub'/'Gitea' browser UI and for use as LLM context (e.g. 'Claude Code'). Reads Rd documentation via tools::Rd_db() (installed packages) or directly from man/*.Rd (development packages, no installation required) and renders one file per topic plus a navigable index.