Customize emails

[kontrollanten]

Describe the problem to be solved There's a lot of use cases about how PeerTube is used, which also creates a lot of needs regarding the communication. Today almost everything is possible to customize, which is wonderful, but as far as I know there's no way to customize the emails sent to the users (verification email and notifications, etc).

Describe the solution you would like: A simple way to customize the emails sent out. The best would be to make them translatable as well.

Describe alternatives you have considered Make it possible to change the root directory provided to email-templates. By adding registerEmailTemplate to RegisterServerOptions we can make it possible for plugins to customize templates. The api could look like

registerEmailTemplate({
  root: '/path/to/pug',
  subject: 'Custom email subject',
  template: 'verify-email',
});

This solution is compatible with #912 as well, since by adding the language as suffix to the template name it can be possible to translate them.