artisan-1.x-dev/artisan_starterkit/artisan_starterkit.libraries.yml

style:
  css:
    theme:
      build/css/style.css: {}
  js:
    build/js/script.js: {}
  dependencies:
    - core/drupal

bs-dropdown:
  css:
    theme:
      build/css/bs-dropdown.css: {}
  js:
    build/js/bs-dropdown.js: {}