Document the changes in the Add Page and the ability to hide cards on it

The Add page will now have a getting started card right at the top of the add page.
The Add page options and structure is changing. Admins will have the ability to hide or remove cards from the Add page.
See these Design docs:
https://docs.google.com/document/d/1NjZG--PnZAUKA7Jot7tlzUxZ3WXxfBLAaz6dk2VgZ7I/edit#
https://docs.google.com/document/d/1x7a9nKdLtExBOxoZHjyr5Pg6yNxrE47UJw8shfuf4Gw/edit
Dev Epic: https://issues.redhat.com/browse/ODC-5013 also see here for latest design docs.

The current Assembly will need to be updated as per the new restructure. Also currently this is an assembly, we might want to convert this into a module.