Serve Zed rZED as https://hypership.space

Summary:
Zed back-end is a PHP application.

Cache and content live in /var/dataroot.
Subfolders follow current repository structure.

Users content is a private repository, and is cloned through deploy key,
using a similar method than for wwwroot51. It benefits from the promotion
of this method for all Alkane in D3187.

Credentials are stored in Vault and deployed through a .env file.
Zed code has been updated to include support for DotEnv.

This configuration scope is nginx and PHP for Zed itself,
the Hotglue builder will need follow-up changes.

Finally, the same pattern we use for Docker services is used here:
a specific pillar file for everything about Zed centralized in one place.

Ref T1676.

Test Plan: Browse https://hypership.space

Reviewers: dereckson

Reviewed By: dereckson

Maniphest Tasks: T1676

Differential Revision: https://devcentral.nasqueron.org/D1586