Thank you for mentioning it! I guessed so, since it’s also missing feature in Jupyter if you want to export in HTML.
Still, I would argue it’s a problem even in the default Jupyter Notebook. That job should not be passed trough Python, but when the notebook is exported. The markdown image feature work in the notebook and while exporting in Latex and PDF. I don’t see why it would not be supported for HTML export.
I know I’m pretty demanding of Datalore team 
, since I ask them for a lot of missing features of Jupyter. (@igro knows that) Still, its hard for them to know how to add value if we do not ask! After that, they’ll be the judge on what to add and what to refuse. I’m poor with javascript and front-end, they know better than me where lies low hanging fruits 
. If I could point them to few, everyone wins.