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.
Based on the work delivered by designers, we simply replicates those
in the storybook documentation in order to centralize everything
related to the Button component.
These files will be used to define the custom design tokens per components.
They are automatically aggregated by the packages/react/cunningham.ts file,
this is why handling typescript config file was important.
