Allow current entity state in entities without repeating entity ID

[twpol]

I am currently unable to show the main entity's state in the entities list without repeating the entity ID. This would normally be fine (apart from extra typing) but I don't see a way to make it work inside custom:auto-entities. I love both these extensions and would love them to work together even better. :)

In #273 (the same issue but for secondary info area), you can specify an icon as a workaround because the icon is ignored there.

This works but repeats the entity ID:

type: entities
entities:
  - entity: person.james_ross
    type: custom:multiple-entity-row
    entities:
      - entity: person.james_ross

This does not work, gives validation error: Entity object requires at least one 'entity', 'attribute' or 'icon'.

type: entities
entities:
  - entity: person.james_ross
    type: custom:multiple-entity-row
    entities:
      - {}

I can see three ways we could make this work:

• Allow no properties (as in my example above) which would use the main entity, state, no icon - exactly as if the entity ID was the only thing specified
• Add a special value to entity that passes validation but refers to the main entity
• Add a special value to attribute that passes validation but refers to the state instead

I haven't been able to find any such special values in the code or documentation, but I might have missed it if they do exist. Sorry if that's the case!