Rolldown is an R Markdown extension that builds scroll-driven HTML documents for storytelling, a.k.a scrollytelling, powered by JavaScript libraries. Currently, only Scrollama is supported.
You can get started with some built-in R Markdown templates in this package. If you use the RStudio IDE, you can create a new R Markdown document from File -> New File -> R Markdown -> From Template. Then find a rolldown template from the list. If you do not use RStudio, you may use the rmarkdown::draft() function to create a new R Markdown document, e.g.,