feat: use email as username

[romulorosa]

Hi everyone,

I would like to propose a feature which in my oppinion improves the overall UX. The idea is to basically use the email as username so that would allow us to remove one field from the # page. The idea came from a real use case for a project that I am currently working on at Anaconda.

I would love to hear oppinions and feedbacks about this approach and also ideas on how to improve the implementation, that is the very first time that I am contributing to this project (which by the way is awesome, thanks!)

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[moraisaugusto]

It would be nice to have this feature.