Is it possible to insert an external pdf between chapters in a bookdown projects? I've found solutions to insert external pdfs at the beginning or end of a project. I also found a solution to collate pdfs from rmarkdown, but this seems to require custom tex packages and configurations. I'm looking for a solution that's more native to bookdown/rmarkdown that will generally just work.
What I'm basically trying to achieve is having a bookdown project that creates a pdf where some of the chapters are created by bookdown and others come directly to me as pdfs from other departments. The key feature I'm looking for within this is the ability to accurately create a table of contents that responds to varying lengths of pdfs to get the corresponding page numbers correct.