[DOCS]: document using routeMeta to redirect to a default path

[AdditionAddict]

Intended PR after '## Route Metadata' section and code

---

Redirect to a default route

To redirect to the route /dashboard from /, define redirectTo and pathMatch inside src/app/routes/index.ts:

import { RouteMeta } from '@analogjs/router';

export const routeMeta: RouteMeta = {
  redirectTo: '/dashboard',
  pathMatch: 'full',
};

---

Or is there a preference to keep using parenthesis index route like src/app/routes/(redirect).ts?

[brandonroberts]

Interesting convention around the (redirect).ts. I think the index.ts would be clearer, as you don't have to name it (redirect) for it to work