(markdown-it-figure) Pass additional classes?

[robdodson]

We have a few classes that authors can apply to an images, for example w-screenshot will put a dark grey border all the way around the image, which is useful if the background of the image is similar to our page background. Or w-fullbleed which will let the image break outside of the page a bit.

We currently use markdown-it-attrs to let authors specify a class or id on an element. Unfortunately it doesn't seem to work with the figure plugin. I'm actually not sure if the responsibility lies with the figure plugin or the markdown-it-attrs plugin. The markdown-it-attrs plugin does support custom renderers so maybe I should see if one of those resolves the issue?

Just sort of brain dumping in this issue in case others run into a similar problem.