AT:

• the email configuration have benn moved into its own json path in the configuration file
• the configuration section in the technical user guide is adjusted accordingly

Context:
Right now, the email configuration need to be configured in the alerting.email.* json path (see docs). However, emails might also be sent in other parts of optimize and do not necessarily have to do something with alerting. Therfore, we should move it to its own json path.