feat(lang/js): add link to Jco book doc on resources - #364

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/cache@v4, actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683, actions/configure-pages@983d7736d9b0ae728b81ab479565c72886d7745b, actions/setup-python@8d9ed9ac5c53483de85588cdf95a591a75ab9f55, actions/upload-artifact@v4, extractions/setup-just@v2. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/