Extensions.Spain

### Please describe why you are requesting a feature

How-to create Extensions.Spain for NIF, NIE, ... step by step

https://es.wikipedia.org/wiki/N%C3%BAmero_de_identificaci%C3%B3n_fiscal
https://www.interior.gob.es/opencms/eu/servicios-al-ciudadano/tramites-y-gestiones/extranjeria/ciudadanos-de-la-union-europea/numero-de-Identidad-de-extranjero-nie/

### Please provide a code example of what you are trying to achieve

Portugal sample:
using Bogus.Extensions.Portugal;
Bogus.Person.Nif() - Número de Identificação Fiscal (NIF)
Bogus.DataSets.Company.Nipc() - Número de Identificação de Pessoa Colectiva (NIPC)

### Please answer any or all of the questions below

* Is the feature something that currently cannot be done?

None

* What alternatives have you considered?

https://geeks.ms/jvelasco/2010/11/04/generador-de-nifnie/

* Is this feature request any issues or current problems?

none

* Has the feature been requested in the past?

I dont know

**If the feature request is approved, would you be willing to submit a PR?**

Yes

Start by comparing the requested Spain extension with the Bogus.Extensions.Portugal example included in the issue, then review the linked NIF and NIE references and the alternative generator. Done means a Spain extension can generate the requested NIF and NIE values with usage consistent with the Portugal sample; the issue names no repository files or tests.

Written by the indexing model from the issue text.