Integrate changelog mail in mailchimp

[mabijkerk]

Background Currently we have a manually updated mailing list for the Deploy changelog mail in Excel. This mailing list exists for 'power users' who work with the API and therefore value updates on changed/new/deleted inputs. There might be users that would also value such a changelog mail, but that we do not know of. These users in their turn do not know of the changelog mail.

Goal Instead of a manual Excel mailing list, manage mail subscriptions to the changelog in the same way as the newsletter. We can then integrate the option of subscribing for the changelog, similar to the newsletter, in the ETM account:

• [x] Setup mailchimp for changelog mail
• [x] Integrate changelog mail option in ETM account
• [ ] Refer to changelog mail option where relevant, for example in What's new and/or API docs
• [ ] Add users from Excel to new mailing list

@noracato @louispt1 does this feel like a complete set of to-do's?

[mabijkerk]

Thanks for this @louispt1, I'll discuss it coming Monday.