Docs site: per-chart prop tables + live examples (beyond playground + API.md)

[benzsevern-mjh]

Why

docs/API.md is a single Markdown file. With ~15 chart types x 27 vibe presets x a brand layer, that doesn't scale — users can't find props, can't preview vibes side-by-side, and the playground (npm run playground) is a single live demo, not a reference.

Spec

• New docs-site/ (or extend playground/) using Astro Starlight (preferred — markdown-first, integrates MDX, ships static).
• Site contents:
  • Getting started (install, quick start, brand vs vibe primer).
  • Per-chart reference page for each component in src/components/: prop table (auto-generated from TS types via react-docgen-typescript or hand-written), 2-3 live MDX examples, gotchas, related primitives.
  • Vibe gallery: one bar chart rendered in every preset, click to see the resolved Rough.js knobs.
  • Brand gallery: same chart across a handful of brand configurations.
  • Recipes: stacked bar, responsive dashboard, dark-mode toggle, export-to-PNG (cross-links to issues BarChart: expose stacked + grouped variants #121, ResponsiveContainer: auto-size charts to parent #120, Client-side export: downloadChart() / toPng() / toSvg() #123, Auto dark mode: brand='auto' honoring prefers-color-scheme #125).
  • MCP section pulled from mcp/README.md with per-tool examples.
• Deploys to GitHub Pages alongside the existing playground, or replaces it.

Acceptance

• npm run docs:dev and npm run docs:build scripts.
• CI builds the docs on PRs; deploys on main alongside the playground.
• All chart components linked from the docs index.

Notes

• Auto-generating prop tables off TS types removes drift between docs/API.md and the actual library.