added explanation about "catch-all" API route that works both on app router and pages router

Author: adguernier

docs/NextJs.md

@@ -141,7 +141,7 @@ Now the admin renders at `http://localhost:3000/admin`, and you can use the Next
 
 ## Adding an API
 
-[Next.js allows to serve an API](https://nextjs.org/docs/api-routes/introduction) from the same server. You *could* use this to build a CRUD API by hand. However, we consider that building a CRUD API on top of a relational database is a solved problem and that developers shouldn't spend time reimplementing it. 
+Never mind the router system you choose, [Next.js allows to serve an API](https://nextjs.org/docs/api-routes/introduction) from the same server. You *could* use this to build a CRUD API by hand. However, we consider that building a CRUD API on top of a relational database is a solved problem and that developers shouldn't spend time reimplementing it. 
 
 For instance, if you store your data in a [PostgreSQL](https://www.postgresql.org/) database, you can use [PostgREST](https://postgrest.org/en/stable/) to expose the data as a REST API with zero configuration. Even better, you can use a Software-as-a-Service like [Supabase](https://supabase.com/) to do that for you. 
 
@@ -170,7 +170,7 @@ SUPABASE_SERVICE_ROLE="MY_SERVICE_ROLE_KEY"
 Create [a "catch-all" API route](https://nextjs.org/docs/api-routes/dynamic-api-routes#optional-catch-all-api-routes) in the Next.js app by adding a `pages/api/admin/[[...slug]].ts` file. This API route redirects all calls from the react-admin app to the Supabase CRUD API:
 
 ```tsx
-// in pages/api/admin/[[...slug]].ts
+// in src/pages/api/admin/[[...slug]].ts
 import { NextApiRequest, NextApiResponse } from "next";
 
 export default async function handler(req: NextApiRequest, res: NextApiResponse) {