docs: Adds docs for Facebook Identity provider

[vfiruz97]

Hi @marcelomendoncasoares,
Adds docs for serverpod/serverpod#4689. Please review when you have a chance.

[marcelomendoncasoares]

Hi @marcelomendoncasoares, Adds docs for serverpod/serverpod#4689. Please review when you have a chance.

@vfiruz97 Nice PR! As a general guideline, I think we can apply most of the comments of the Microsoft docs PR here as well (title casing/style guide adjustments, usage of the *FromPasswords class on the configs examples, GetExtraFacebookInfoCallback). Could you pair them up and make a review based on that feedback? Then I can quickly scan if there is something else left.

[vfiruz97]

Thanks, @marcelomendoncasoares ! I've applied the same suggestion we used for Microsoft, and everything should now be aligned. It's ready for your review.
Once this doc is approved, I'll reorder the providers in the final commit as follows:

01 – anonymous
02 – email
03 – google
04 – apple
05 – facebook
06 – passkey
07 – firebase
08 – github
09 – microsoft
10 – custom-providers

Looking forward to your feedback.

[vfiruz97]

To make things easier, I also recorded a full end-to-end test (sped up) to demonstrate how everything is set up and working.
Sign in with Facebook e2e test in Serverpod

[marcelomendoncasoares]

Great work with the revision! LGTM 🚀

Regarding the order you have proposed after this merge, I have just one minor suggestion to move passkey last:

01 – anonymous
02 – email
03 – google
04 – apple
05 – facebook
06 – firebase
07 – github
08 – microsoft
09 – passkey
10 – custom-providers