Jupyter Backend

[boisgera]

TODO:

• [x] Solve missing imports
• [x] Map to GFM (e.g. to get the proper map support)
• [ ] Internal links (generate dummy ids/span)
• [x] Typography : "--"
• [ ] Color backgrounds ? (Not sure it's possible; not unless we convert the whole block to HTML?)
• [ ] Need to normalize the size of images and drop the special attributes that are not rendered (?)
• [x] Support for videos.
• [ ] Can't split code in multiple cells once figure() appears