The row of sections under the header, on documentation pages only.

## Usage

```vue
<DuxtSections />
```

## API

No props. Reads `sections`; renders nothing when that list is empty.

## Notes

It sits with the docs rather than in the global header, because the landing page
has no sections to show.

A section is rarely the page itself — it is the branch the page sits in. So the
exact match announces `aria-current="page"` and an ancestor announces `true`,
which is the distinction `aria-current` exists to make.