Add prepare hook to run build when installed as git dependency directly

[kindjie]

Issue

Currently, adding chess.js as a dependency from npm works without issue, i.e. npm install chess.js. However, adding it as a git or Github dependency directly using npm install github:jhlywa/chess.js (or similar) will cause an import error.

Installing the dependency from a git repo directly is required to use commits after the most recent npm published version.

Cause

For example, Vite may give: Failed to resolve entry for package "chess.js". The package may have incorrect main/module/exports specified in its package.json.
This occurs because the chess.js package.json specifies paths in the dist directory that doesn't exist until npm run build is done.

Solution

This PR adds a prepare hook that triggers npm run build in the following cases:

prepare (since [email protected])

• Runs BEFORE the package is packed, i.e. during npm publish and npm pack
• Runs on local npm install without any arguments
• Runs AFTER prepublish, but BEFORE prepublishOnly
• NOTE: If a package being installed through git contains a prepare script, its dependencies and devDependencies will be installed, and the prepare script will be run, before the package is packaged and installed.
• As of npm@7 these scripts run in the background. To see the output, run with: --foreground-scripts.

See: npm CLI life cycle scripts documentation.

This is a tiny change to package.json.

[jhlywa]

Thanks for the PR!