Once we have a Whonix-Host ISO, we need user documentation on how to write it to DVD or USB for major operating systems such as Windows, Linux, macOS.
After that users should be able to boot the iso and use Whonix-Host Live Mode and/or to start Whonix-Host Installer (calamares).
Installing Whonix-Host without installer (calamares) is out of scope in this ticket since discussed in seaprate ticket T909.
Other Open Source Linux distributions might have this documented already while using a Libre documentation license. In that case we could adapt the documentation and wouldn't need to re-invent it from scratch.