I see that fenced divs (i.e.,using :::) work in the new versions of rmarkdown (https://github.com/rstudio/rmarkdown/releases, https://bookdown.org/yihui/rmarkdown-cookbook/custom-blocks.html). And it worked out of the box both in html_documents and pdf_documents, but it didn't work in bookdown::pdf_book or bookdown::gitbook.
Is there something that I need to change in the yml config?