[developer-experience] Use commit hooks to format staged files in Javascript projects before git commits

Motivation

Enable formatting issues to be automatically handled locally instead of only erroring in CI.

This reduces wasted CI minutes, and enables developers to have their code per project guidelines after every commit (within seconds), instead of having to wait several minutes for CI to run.

vega/editor already does this.

Projects to modify

(assuming each one has eslint and package.json set up already)

• vega: https://github.com/vega/vega/pull/4230
• vega-lite: https://github.com/vega/vega-lite/pull/9763
• react-vega: https://github.com/vega/react-vega/pull/660
• vega-embed: https://github.com/vega/vega-embed/pull/1517
• vega-tooltip: https://github.com/vega/vega-tooltip/pull/1152
• vega-themes: https://github.com/vega/vega-themes/pull/775
• vega-datasets: https://github.com/vega/vega-datasets/pull/759
• svelte-vega: https://github.com/vega/svelte-vega/pull/1079
• ts-json-schema-generator: https://github.com/vega/ts-json-schema-generator/pull/2465