We want to be able to visualize easily themes directly inside
Storybook. This was not a trivial task as there is no centralized
logic to handle Doc / Stories / Manager at the same time.
In order to make the storybook visible to everyone. Some changes
had to be made to make index.scss compiled with the rest of the
codebase, it had to be imported from preview.js, not directly from
preview.html.
