Switch

A toggle that is a real checkbox underneath, with role="switch".

A switch built from a `<div>` and an `onclick` is not a switch for anyone but
the person who can see it. This one is an `<input type="checkbox">` with
`role="switch"`, so keyboard operation, form submission and "jump to next
control" all work without us writing them — and `aria-checked` says on or off
rather than checked or unchecked.