Enum renders kind of weird

# Provide a minimally reproducible example

```
#| export
from enum import Enum

#| export
class Role(Enum):
SYSTEM = "system"
USER = "user"
ASSISTANT = "assistant"
FUNCTION = "function"
```

creates the following doc:

Start by reproducing the provided Python Enum example in nbdev and compare its generated documentation with the screenshot in the issue. Trace the documentation-rendering path responsible for enum output; done means the generated enum documentation renders clearly and the example remains covered by a regression test.

Written by the indexing model from the issue text.