Should be doable by making a macro return a block where the first expression execute the Julia code and the second expression (the one that is sent to the Pluto output) returns an Html with Javascript inside a script tag that modifies the cell to markdown and then rerun it…
Not at the computer to try it now though
Edit:
I did have a chance to try this and indeed it is possible:
And here is the link to the notebook code for testing:
Note that this is somehow a hacky solution which might not work anymore when Pluto changes to CM6 (don’t know how long it’ll take), or in general with new versions of Pluto.
But overall it still highlight the amazing capabilities of Pluto!