[📚] firebase_auth example README is outdated

[AlexV525]

Setting up federated identity & social sign-in with the example does not follow the latest documentation in https://firebase.google.com/docs/auth/flutter/federated-auth.

[SelaseKay]

Hi @AlexV525, thanks for raising this. Just to clarify, when you mention "the example," are you referring to a specific sample in the FlutterFire repo, or something else? I'd like to make sure I fully understand the context.

[AlexV525]

are you referring to a specific sample in the FlutterFire repo, or something else?

I'm referencing this: https://github.com/firebase/flutterfire/blob/main/packages/firebase_auth/firebase_auth/example/README.md

[MichaelVerdon]

Hi there @AlexV525 can you please be more specific? Like give me what line in the README is not correct and maybe what is should? Feel free to open a PR yourself if you would like to but otherwise I am happy to change it once I understand it.