Explore a "drawer" for the service navigation

[domoscargin]

What

• Add a button to the end slot which collapses or expands a "drawer" underneath the service navigation
• Users may pass in a list of navigation items to appear in the drawer
• The drawer is visually connected with the button that activates it

Why

We want to provide a way for folks to fit things like languages into the service nav without overwhelming. This could also be an approach to sub menus down the line.

Who needs to work on this

Developer, designer, accessibility specialist

Who needs to review this

Developer, designer, accessibility specialist

Done when

• We have a prototype with this behaviour
• We have decided whether this functionality is shippable