Pack11ty now uses Eleventy v3

Pack11ty is now based on the Eleventy v3 version!

Also, the code has been fully rewritten to integrate modern JavaScript features like ECMAScript Modules (aka ESM), just like Eleventy.

Both the plugin and the template repository (aka Eleventy Starter) have been updated.

Also, the assets are now processed with a combination of Eleventy's Custom template languages, Render plugin and Bundle plugin. sass and esbuild are used to process Sass and JavaScript code directly within Eleventy build process. For example, for JavaScript assets, the external build script with Rollup, Babel, Terser, etc., is gone.

There are still some missing parts in the documentation, or some that need updates, it will be done ASAP.

Feel free to open an issue is you find bugs or struggle using this new version.