Docs draft: https://docs.google.com/document/d/1KQc__8JASgCs_FiQID7pVp_CcEYW0SebQ03QR7-bQ50/edit?tab=t.0

We need to tell users how to perform the following on image-mode hosts:

• Launch updates
• Change the target image
• Rollback to the previous target image

We also need to explain how they can tell if an image-mode host needs updates.

The new image mode overview page likely could be documented via a release note since it's self-explanatory.