Callout boxes for ipynb output

Discussed in https://github.com/quarto-dev/quarto-cli/discussions/1166

^{Originally posted by linogaliana June 17, 2022}
Hi,

callouts are a really nice feature. I have seen in the doc that currently Jupyter Notebooks are not supported (https://quarto.org/docs/authoring/callouts.html). I totally understand this is not a priority and might be tricky to implement. However, in the future, that would be really cool to also propose boxes for this output format.

• As far as I understood discussions in https://github.com/jupyter/notebook/issues/1292 it seems that there exists some features in Jupyter Notebook with some raw HTML <div>. Some examples are given here
• However, all boxes provided by quarto are not supported
• Boxes are not as aesthetic as those provided by quarto (or jupyterbook). This is of course not a priority (functional boxes would first be great) but this would be cool to a nice box in notebook. I saw that it is possible to embed some styling element directly in the div (see this stackoverflow thread) but maybe there's a better way to start
• @choldgraf maybe has an opinion on the best way to proceed

Once again, I understand that tweaking some notebook features is not a priority. But helping python users generate nice notebooks from quarto could be appreciated