Description of the problem:
There is no documentation how to deploy disconnected environment for various versions (1.3, 1.4 and 1.5)

How reproducible:
100%

Steps to reproduce:

1. Navigate to https://www.rhdhorchestrator.io/main/docs/installation/

Actual results:

We have installation steps for deploying from scratch and for existing RHDH.

Expected results:

There should be section for disconnected environment with list of images.