initial changes for the new horizontal menu system

css/styles.css

js/component_scripts.min.js

source/_data/design-tokens.artifact.yml

source/_patterns/00-config/_breakpoints.scss

source/_patterns/00-config/_design-tokens.artifact.scss

source/_patterns/00-config/config.design-tokens.yml

source/_patterns/03-layouts/header/_header.scss

source/_patterns/03-layouts/header/header.twig

source/_patterns/03-layouts/header/header.yml

...e/_patterns/03-layouts/site-container/site-container.twig

...ce/_patterns/03-layouts/site-container/site-container.yml

source/_patterns/04-components/menu/_menu.scss

...atterns/04-components/menu/menu--header/menu--header.twig

...patterns/04-components/menu/menu--header/menu--header.yml

...4-components/menu/menu--horizontal/_menu--horizontal.scss

...s/04-components/menu/menu--horizontal/menu--horizontal.js

...s/04-components/menu/menu--horizontal/menu--horizontal.md

...04-components/menu/menu--horizontal/menu--horizontal.twig

.../04-components/menu/menu--horizontal/menu--horizontal.yml

.../_patterns/04-components/menu/menu--main/_menu--main.scss