We need to add a new section -  OpenShift Migration

I would probably place it between the MTC and the Backup and Restore docs

• Backup and Restore
• NEW SECTION
• Migration from OpenShift Container Platform 3 to 4 overview 

The contents of this section is to be created from https://docs.google.com/document/d/1vy4s5FDTb3ovkGJ9ln4R5UQf3YvHw39rXnqx0k7ucY8/edit?tab=t.0

This should be done As Soon As Possible, as we're sunsetting MTC and this document should be in place for the sunset plan to move forward