docs(api-routes): fix node docs links (vercel#34125)

## Documentation / Examples

- [x] Make sure the linting passes by running `yarn lint`

docs/api-routes/introduction.md

@@ -29,8 +29,8 @@ export default function handler(req, res) {
 
 For an API route to work, you need to export a function as default (a.k.a **request handler**), which then receives the following parameters:
 
-- `req`: An instance of [http.IncomingMessage](https://nodejs.org/api/http.html#http_class_http_incomingmessage), plus some [pre-built middlewares](/docs/api-routes/api-middlewares.md)
-- `res`: An instance of [http.ServerResponse](https://nodejs.org/api/http.html#http_class_http_serverresponse), plus some [helper functions](/docs/api-routes/response-helpers.md)
+- `req`: An instance of [http.IncomingMessage](https://nodejs.org/api/http.html#class-httpincomingmessage), plus some [pre-built middlewares](/docs/api-routes/api-middlewares.md)
+- `res`: An instance of [http.ServerResponse](https://nodejs.org/api/http.html#class-httpserverresponse), plus some [helper functions](/docs/api-routes/response-helpers.md)
 
 To handle different HTTP methods in an API route, you can use `req.method` in your request handler, like so: