[FEAT] Make the `rollup` project use the shared CSS files

Currently, the `rollup` project use a CSS file which is fully duplicated with the shared CSS file: https://github.com/maxGraph/maxgraph-integration-examples/blob/v0.4.1/projects/rollup-ts/public/style.css

Let's find a way to use the shared CSS files.
For example, we may use https://www.npmjs.com/package/rollup-plugin-import-css