Also, as we point out in the READMEs and the pkgdown documentation, much of the documentation is expanded upon in the relevant chapters in R for Data Science (freely available online)!
e.g. for purrr
The scoped variants are relatively new, and we are currently in the process of upping their documentation.
Suzan Baert has some great material on lesser-known dplyr functions (I collected some in a Twitter moment when she was curating the rotating R Ladies account):
And she has more in this repo:
And in a series on her blog:
For purrr, I rounded up some of my favourite resources here, which includes a great series of posts by Colin Fay.