nbdev3: show_doc() regression

[ericjtaylor]

In nbedv2, show_doc() produced beautifully formatted documentation, with the docments comments displaying in a table but not the code. For example, see the say_gday() function in the show_doc() documentation:

https://web.archive.org/web/20251205204719/https://nbdev.fast.ai/explanations/docs.html#how-show_doc-works

In nbdev3, the output is in comparison quite basic. There is no table and the docments comments remain in the code:

https://web.archive.org/web/20260109161133/https://nbdev.fast.ai/explanations/docs.html#how-show_doc-works

Given how proudly Jeremy and Hamel demonstrate the nice table formatting in their tutorial, I assume this is an unintended bug?