nbdev

Version: 1.2.2

Summary of issue
Including a @dataclass decorated class breaks getsource in show_doc

Minimal example

• Clone nbdev_tutorial
• Add new cell in 00_core.ipynb

#export
from dataclasses import dataclass

@dataclass
class Foo:
    a: int
    b: str
    c: float

• Run nbdev_build_lib
• Run nbdev_build_docs

nbdev_build_docs

At the moment, it's possible to do

toc: true

to autogenerate a table of contents. I think it would be nice if there were also styling options, e.g. to have that TOC float on one side of the page.

Motivation

ipyannotator currently support image labeling. However, for data sets with a very large number of classes it's very difficult to
quickly match the image to the right class.

Showing an visual representation for all possible classes and there textual description right next to the image could considerable improve the process. Currently only a textual or a visual represen