flow in markdown quarto

[moodymudskipper]

For some reason I never got it quite right, but I think I was hoping that the default printing would include the diagram in the doc, I think we might have out = "report" that uses knits::include_graphics() on a temp png file.
I don't remember why it was a challenge to recognise that we're knitting and adapt the behavior, there should be an env variable.
Let's have another pass on this.

[moodymudskipper]

From opt::opt$knitr$ I found getOption("knitr.in.progress"))

opt::opt$knitr$knitr.in.progress
#> Call `opt$knitr$knitr.in.progress()` to get and `opt$knitr$knitr.in.progress(value)` to set.
#> This option is used by : `` `knitr::spin_child()` ``

It seems that it's not properly documented but further research indicates that Yihui recommends it for some cases: yihui/knitr#926