Outdated documentation for base type for enum
Last paragraph in https://doc.kaitai.io/user_guide.html#enums states:

> We add enum: …​ parameter to every attribute that’s going to be represented by that enum, instead of just being a raw integer. **Note that such attributes must have some sort of integer type in the first place (i.e. type: u\* or type: s\*).**

Emphasized is not true. Enums can also be based on strings