Docs: update link.mdx (#61508)
Updated paths in relation to `<Link />` and middleware rewrites. Feel
free to leave suggestions if needed, this has always confused me a
little bit.
**Old Version**:
For example, if you have a Dynamic Route like `/dashboard/[user]` that
you want to present differently via middleware, you would write: `<Link
href={{ pathname: '/dashboard/authed/[user]', query: { user: username }
}} as="/dashboard/[user]">Profile</Link>`.
The `as` prop should be the URL we want to display while href/pathname
is the actual path. So if we want to present something differently via
middleware, we would do so via `as`. In the example above we want to
display `/dashboard/[user]` differently but we use
`as='/dashboard/[user]'`.
