Add Brazilian citizen id and its docs

[vbrazo]

This feature request should be assigned to a Brazilian. If you're interested, please drop us a line.

If you'd like to understand more about this issue, you should check Faker's Spanish citizen id and docs PR: #1147 out. The idea is pretty similar, but we'd like to add Brazilian locales.

[vbrazo]

@lucasqueiroz check this issue out and let me know if you'd be interested in working on this feature.

[lucasqueiroz]

I'd be interested, but I have limited time this week. I can work on this on the weekend, probably. If anyone wants to do it before, feel free :)

[vbrazo]

@thalesap you could work on this

[lucasqueiroz]

Just making sure, would this be for CPFs or RGs? Or both? Also I haven't found any reference about how to calculate the RNE (Registro Nacional de Estrangeiros) number. Should we leave this number out?

[vbrazo]

I think we could have both methods. How does that sound to you?

[vbrazo]

I think CPF is like SSN and ID is like RG for us.

[lucasqueiroz]

Sure, both are really simple to implement

[lucasqueiroz]

I believe there is a base 10/11 method already, so wouldn't be too hard

[vbrazo]

thanks @lucasqueiroz