Entity_registry.yaml file missing in config folder

I recently updated to HASSIO 63.3 and all the device_tracker entities in my known_devices.yaml where all renamed andI miss some groups on the frontend due to this. I saw on the forum that with this new version there should be a entity_registry.yaml file created in the config folder. But this is not de case at my installation. Can I create entity_registry.yaml file myself and how should it look like ? Is het just a copy of the known_devices.yaml file. Is there somewhere some information about this entity_registry.yaml file ?