chore(express): docs copy and code example cleanup (#10061)

Co-authored-by: Nico Domino <[email protected]>

packages/frameworks-express/src/index.ts

@@ -31,7 +31,7 @@
  * You will also need to load the environment variables into your runtime environment. For example in Node.js with a package like [`dotenv`](https://www.npmjs.com/package/dotenv) or `Deno.env` in Deno.
  *
  * ### Provider Configuration
- * The callback URL used by the [providers](https://authjs.dev/reference/core/modules/providers) must be set to the following, unless you mount the `ExpressAuth` handler on a different path:
+ * The callback URL used by the [providers](https://authjs.dev/reference/core/providers) must be set to the following, unless you mount the `ExpressAuth` handler on a different path:
  *
  * ```
  * [origin]/auth/callback/[provider]
@@ -66,7 +66,7 @@
  * This can either be done per route, or for a group of routes using a middleware such as the following:
  *
  * ```ts
- * export function authenticatedUser(
+ * export async function authenticatedUser(
  *   req: Request,
  *   res: Response,
  *   next: NextFunction