Add `rel` to more places

## Base template

```html
<link rel="preconnect" href="https://fonts.googleapis.com">
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
```

## About page

- add `ref="alternative" type="application/atom+xml"` to the feed links

## Article nav

- add `rel="archives"` to all tag and archive links