Update package.json with appropriate Sass package importer instructions

[sebnitu]

Problem

There's currently still in development the implementation of the package importer for Sass. This should in the future use the package.json to correctly resolve package imports/use/forward calls. Keep an eye on this so that once it has been implemented I can update the package.json exports property and remove a lot of the currently required root forwarding files such as:

• ./config.scss
• ./usage.scss
• ./css.scss
• ./palette.scss
• ./theme.scss
• ./root.scss

References:

• https://sass-lang.com/documentation/js-api/classes/nodepackageimporter/
• https://sass-lang.com/blog/announcing-pkg-importers/
• https://sass-lang.com/blog/rfc-package-importer/

GitHub issues:

• Support for SASS nodeJS package importer vitejs/vite#16438
• Use the modern SASS compiler API vitejs/vite#7116