To use this example you have to have Node.js installed and a package manager with it. I recommend using yarn, but npm will work just as fine for a simple example like this.
Install packages and run startup script:
npm install
npm start
or
yarn
yarn start
ESLint is used to check your JS code for errors, so make sure to install the following extension in VS Code: dbaeumer.vscode-eslint.
Parcel will then start a development webserver and use your index.html as an entrypoint. It will then resolve references to CSS and JS files and compile these automatically whenever a file is saved.
You can configure additonal PostCSS plugins inside .postcssrc and change the supported browsers for autoprefixer inside .browserslistrc. I have included Internet Explorer 9 for testing purposes.
Parcel also transpiles your modern JavaScript using the browserslistrc config as a reference tu support older browsers. This is done using the config in babelrc.
After compilation you can check the dist folder to see what Parcel has written to the output files.
https://parceljs.org/javascript.html