Add email address to Code of Conduct

[joshkempner]

Is your feature request related to a problem? Please describe.
The code of conduct requires users to send reports via Slack. It would be best if they could use email instead.

Describe the solution you'd like
Set up "conduct@reactivedomain.org" for reporting code of conduct violations. In addition, we should have a general email address "maintainers@reactivedomain.com" for more general emails.