That's not planned on the 0.1.0 roadmap, so I suppose it's not a priority for now.
Maybe someone will release an extension to implement such a feature (it's quite a popular request).
I'm not a coder, but I think that can be adapted: https://github.com/Gargron/fileupload
(Or when a markdown editor will be added. Some have image upload, like this one or this one)