Possibility of supporting `username-rules`

[dudeofawesome]

A number of password managers now support username generation as well as password generation.

• https://bitwarden.com/blog/how-to-use-the-bitwarden-username-generator-and-why-you-should/
• https://1password.com/username-generator

I wonder if this repository should start collecting username format rules for all the same reasons it collects password rules?

For example, TransUnion does not support certain special characters in your username (_) and will silently drop them from the username.

[rmondello]

This is interesting, and likely a good idea. Although Apple is unlikely to pursue this idea in the short-term, the project would happily receive contributions in this area.

[adwaitjr10]

Alright, rolling up my sleeves!