[Form] `EnumType`: `choices` is missing

`choices` is missing on https://symfony.com/doc/current/reference/forms/types/enum.html

I don't think that the text from https://symfony.com/doc/current/reference/forms/types/choice.html#choices can be reused, cause it mentions `true`/`false` as examples (i.e. no enum cases).
Besides, I couldn't get it to work to use the array keys as labels - is that working differently in an `EnumType`?