Out of date custom mailer docs

[mdodell]

I noticed that these docs were fairly out of date - Sidekiq now calls workers 'jobs'. There is also a send_email function which I believe is where we should be sending emails from.

I'm trying to set up Rodauth with a custom mailing system using Sendgrid or Postmark. Could these docs be updated as that feels like a common use case?

[janko]

The wiki is publicly editable, so feel free to correct any outdated terminology/API.

As for send_email, I'm not sure how it could be used here. It receives the result of create_*_email methods as the argument, but not sure what that object could be. Unless I'm missing something, overriding send_*_email seems correct here.