Bureau structure page

- Add bureau structure page contents.
- Add content slider functionality for mobile org chart.
- Add jump-link__back & jump-link__bg modifiers.
You could ditch these two properties `width` and `text-align` if you add them to `.jump-link`. What's going on here is `.jump-link` doesn't work well with `<button>`'s yet because `<button>`'s default to auto width and text align center.