Add Mozilla Code of Conduct file (#400)
Add Mozilla Code of Conduct file (#400)

Fixes #399.

_(Message COC002)_
mozilla/lumbergh,glogiotatidis/lumbergh,glogiotatidis/lumbergh,mozilla/lumbergh,glogiotatidis/lumbergh,mozilla/lumbergh,glogiotatidis/lumbergh,mozilla/lumbergh