Migrate how the project is requiring dependencies. Mainly influence lib/ and test/ directory.
Use npm run start to start the app, or npm run live to live-reload when making changes.

Main changes:

• Use import ./xx.js instead of 'require('./xx')'
• when importing JSON, because the failure for ES6 to import JSON, use function:

// e.g. in app.js
import { importJSON } from './lib/util.js';
const { version } = importJSON('./package.json', import.meta.url);

• Turn off import/extensions, although airbnb-code-style prefers it, it's using experimental features.