Instructions to run locally

[nicoabie]

It would be nice if instructions to run it locally are provided in order to test changes and be able to contribute with solutions to the proposed exercises.

[caugner]

Most of the CSS examples in this repository contain an index.html that can be opened directly in the browser. 🙂

[nicoabie]

Maybe adding a comment in the readme?

[caugner]

Feel free to open a PR. 🙂