Zun Installation Documentation (source/install)

Introduction:

This directory is intended to hold any installation documentation for Zun. Documentation that explains how to bring Zun up to the point that it is ready to use in an OpenStack or standalone environment should be put in this directory.

The full spec for organization of documentation may be seen in the OS Manuals Migration Spec <https://specs.openstack.org/openstack/docs-specs/specs/pike/os-manuals-migration.html>.