✨ Update script to build scss files along css files

This PR will rename `scripts/build-css-modules.js` to `scripts/build-stylesheets.js` and update the script to export `scss` files along with `css` files. ### Fix Fixes #18 ### Checklist: - [x] Give a generic name to the script file `build-css-modules`. - [x] Update code to generate `scss` files. - [x] Update the build script. - [x] Check if files are being build successfully.