Support Julia REPL help mode

[MHellmund]

With QuartoNotebookRunner 0.4.0,

 ```{julia}
 ?for
 ```

is a Julia parse error. It works for me with Quarto/IJulia: https://www.math.uni-leipzig.de/~hellmund/juliabook/chapters/first_contact.html#sec-tab

[MichaelHatherly]

It would be possible to support something like REPL modes most likely. Happy to accept PRs for this.

[MHellmund]

closed by https://github.com/PumasAI/QuartoNotebookRunner.jl/pull/121