Split this repo into 2 different repositories

[bellons91]

It would be great to have 2 separate repositories for this theme: one for the theme itself and one for the demo.

In this way, new users can easily understand how to integrate the npm package and how to configure the site.

At the same time, contributors can work on the theme and release new versions, fix bugs, add improvements, and so on.

(this issue comes from my experience applying this theme: I found it very difficult, and I think that having a simple demo repository can help new users approaching this theme)