Github Dark Mode Image Support

[mwarkentin]

I was directed here from pypi/warehouse#11251.

What's the problem this feature will solve?
Github supports rendering a specific image for light vs. dark mode by actually specifying two images. Here's an example PR: getsentry/sentry#33799

However when the .md file is rendered elsewhere (like pypi) it would show up as 2 images.

Describe the solution you'd like

I'm wondering if it would make sense to have an option that would let you specify light / dark mode when rendering and hide / show the images as they do on Github? Defaulting to rendering light mode only or ignoring the mode probably makes sense.

Additional context

• https://docs.github.com/en/get-started/writing-on-github/getting-started-with-writing-and-formatting-on-github/basic-writing-and-formatting-syntax#specifying-the-theme-an-image-is-shown-to
• getsentry/sentry-python#1342
• microsoft/vscode#139556
• https://github.community/t/support-theme-context-for-images-in-light-vs-dark-mode/147981

[mbarkhau]

I'm sorry, but I think this is out of scope for this library. theacodes/cmarkgfm is just a python wrapper around github.com/github/cmark-gfm, so unless this is supported by the underlying C library, I don't think here is the right place for your request.

If you have a more concrete idea of how to proceed with an implementation here, feel free to reopen the issue.