List all mandatory indexes to run MongoDB safely

Important indexes have been added after the releases of Nuxeo 9.10 and 10.10, like ecm:id, ecm:isTrashed or ecm:retainUntil.

The problem is that Nuxeo won't work properly without these indexes but Nuxeo code is not touching an existing MongoDB database to add these indexes.

So we should update https://doc.nuxeo.com/nxdoc/mongodb/ to list all the required indexes. The list can be built from the class MongoDBRepository which creates all these index for an empty repository

It could also be part of the upgrade documentation.