Use HTML emails for communication

[salmar]

Is your feature request related to a problem? Please describe.
All emails sent by Alf.io are in plain text which lacks structure and looks poor from a user perspective

Describe the solution you'd like
As communication is an important part of the platform, I suggest to move to HTML emails (HTML with plain text alternative)

Describe alternatives you've considered
In order to have responsive emails, a framework like MJML could be used.

[tobsowo]

Hope this get released soon.