[BUG] routes.ts is invalid because of missing route helper second string argument

[redasalmi]

What version of React Router are you using?

v7

Steps to Reproduce

• init a react-router v7 app
• create a routes.ts file and copy this code from the documentation

import {
  type RouteConfig,
  route,
  index,
  layout,
} from "@react-router/dev/routes";

export const routes: RouteConfig = [
  index("./home.tsx"),
  route("about", "./about.tsx"),

  layout("./auth/layout.tsx", [
    route("login", "./auth/login.tsx"),
    route("register", "./auth/register.tsx"),
  ]),

  route("concerts", [
    index("./concerts/home.tsx"),
    route(":city", "./concerts/city.tsx"),
    route("trending", "./concerts/trending.tsx"),
  ]),
];

• start the dev server

Expected Behavior

the dev server should start and it should render the routes defined in the routes.ts file

Actual Behavior

• the dev server crashes and logs:

Route config in "routes.ts" is invalid.

Path: routes.1.file
Invalid type: Expected string but received Array

I see that in the route helper function definition that it expects a second string argument, by adding that it fixes the issue but it'll render the child routes under it as nested layouts.
this could be just a documentation issue but copying a lot of examples from the dev branch routing guide crashes the app https://reactrouter.com/dev/guides/start/routing