readme

# markdown:readme — Document the repo in its README Scan the repository and write (or update) its **README**, following the **documentation-standards** skill (writing style, tables, and the mermaid diagram rules). Default the target to the current repo root; if `$ARGUMENTS` names a directory, operate on `<dir>`. Update an **existing** readme in place — preserve its filename and casing (`README.md` / `readme.md`); otherwise create `README.md`. ## Required sections (in this order) The README must contain these, top to bottom: 1. **Title** — the project name as the `#` H1. 2. **Short description** — one or two sentences on what the project is and does. 3. **List of projects** — every project/package in the repo (a table for a monorepo; a single entry for a polyrepo). 4. **Architecture** — a `mermaid` diagram of how the projects/services fit together, plus the important notes a reader needs (boundaries, data flow, key decisions). 5. **Infrastructure** — every cloud tool/service the repo uses. 6. **Local Development** — a step-by-step guide to run the repo locally. 7. **Projects** — one detailed section per project (monorepo) or a single project section (polyrepo). 8. **Important tasks** — the commands a developer runs day to day, from the repo's task runner (omit if the repo has none). When updating, **refresh these eight in place and keep every other section** an existing README has (License, Contributing, badges, …) — never delete them. ## 1. Detect (scan ...