Migrating from 3 to 4: Compatibility guidelines

What needs fixing?

This guide is only for migrating from 3.x to 4. So "OpenShift ... 4.5 or later" should be changed to "OpenShift 3".
We assume that the latest version is the target cluster, so "OpenShift 4.6 later" should be changed to the current version (4.10).
The upper left cell (Legacy 1.7 operator...") should probably be removed because it is for OpenShift 4.2-5.
The lower right cell (MTC 1.6) should probably be removed because it is not relevant.|