Create coming soon page for ECRI

Content: https://docs.google.com/document/d/1RES8tYwecoEnNtRFefLe_K8zsP3X0P9Y12G4y4qhQXQ/edit?usp=sharing

Background image: to be provided by @mkokabi

@mbarbero I know you had already done some work on setting up the repo with @cguindon but I assume his team will be the ones setting up the landing page?

CC @scorbett