rinoa: first draft of nginx frontend

Summary:
This is the first draft of the nginx frontend for `darcs.haskell.org` AKA `rinoa`. This adds the SSH key information for Malcolm Wallace, and adds a faithful nginx frontend.

Signed-off-by: Austin Seipp <aseipp@pobox.com>

Test Plan: Run `nixops deploy --include darcs`, and watch it fail because there are no certificates yet.

Reviewers: hvr, relrod

Differential Revision: https://phabricator.haskell.org/D7