Currently, I have a bookdown project structure similar to the one that is recommended: 12.2 Project structure | R Markdown: The Definitive Guide
However, these files are becoming long. I am using subchapters, and subsubchapters, etc.
Is there a way to break up these .Rmd files, and make subchapters into chapters, and subsubchapters into subchapters? And then group the chapters into "parts?"Perhaps there's some lesser-known option I can specify for _bookdown.yml.