js 0.3.0

The JS rim covers the grammar, proves it against the crate, and stops leaking
wasm handles.

• Marks: Cells (matrix / rgb / classes), Range (xy / y / over,
  body, marker), Bars.spans / Bars.at / Bars.base. Plot.palette,
  Palette, Colormap, tableWith.
• Mapping and Viewport are JS values. You never call free().
• Shared goldens: tests/fixtures/js/goldens.json, written by
  cargo run --example js_goldens --features serde, checked in CI against both
  the crate and wasm.
• npx malevich — a tour, or line / hist / bar from stdin.
• Plot.renderPixels / Plot.renderBest (JS sniffs the environment; wasm
  never does). PlotColumn injects Ink origin from siblings above.
• npm README uses the crate's showcase screenshots.

https://www.npmjs.com/package/malevich/v/0.3.0