{catchup} version 0.0.1

This is the first experimental version of the {catchup} package. It contains the basic core functionality the package was created to offer, and is documented, installable, and passing R build checks. This version is suitable for testing for personal use, but probably won't be watertight and bug-free, given that it's essentially the first draft of the package.

Any help in testing and tightening the package is appreciated.