Use upstream markdown2

[dvzrv]

Problem Description

Hi! 👋
I'm currently looking into packaging pdoc for Arch Linux.
I noticed that you are vendoring markdown2 from a custom location, which seems to be an outdated version of https://github.com/trentm/python-markdown2

As packager it is not clear to me what the upside of vendoring this (still actively developed) library is.

Proposal

It would be great to rely on https://github.com/trentm/python-markdown2 (this is packaged in many distributions) instead of vendoring an older copy of it.

Alternatives

Keep on vendoring.

Additional context

Distributions usually strive to have only one version of a given thing available in the repository, as that is easier to handle in security related situations.
See also Fedora's good write up on bundled libraries.

[mhils]

As packager it is not clear to me what the upside of vendoring this (still actively developed) library is.

We used to occasionally carry custom patches. Upstream markdown2 should be fine nowadays. Happy to take a PR that changes it!

[dvzrv]

Thanks for the background info!

I'll try to provide a PR in the coming days then! :)