Performs set up for checking the reverse dependencies of an R package, as implemented by the revdepcheck package:
Adds revdep directory and adds it to .Rbuildignore
Populates revdep/.gitignore to prevent tracking of various revdep
artefacts
Creates revdep/email.yml for use with revdepcheck::revdep_email()
Prompts user to run the checks with revdepcheck::revdep_check()
use_revdep()