Feature: `FileTree` Component

Currently the easiest way _(excluding custom components)_ to visualize a directory structure is to use an ascii-based tree as follows:

```
your_app/
├── pubsepc.yaml
├── lib/
├── ...
└── widgetbook/
├── pubsepc.yaml
├── lib/
└── ...
```

Providing first-class support for this might be a good idea, to make docs more visually appealing.
Here are some examples:

1. [Nextra's `FileTree`](https://nextra.site/docs/guide/built-ins/filetree) - Simple and interactive file tree.

1. [From Next.js docs](https://nextjs.org/docs/app/building-your-application/routing/pages-and-layouts) - They have a more visually appealing style, they use images instead of components to be able to annotate their images.