Started documenting the rrule type.
Started documenting the rrule type.

sprymix/dateutil,abalkin/dateutil,pganssle/dateutil-test-codecov,adamgreig/python-dateutil,pganssle/dateutil-test-codecov,abalkin/dateutil,mjschultz/dateutil,Bachmann1234/dateutil,sprymix/python-dateutil,emsoftware/python-dateutil,jenshnielsen/dateutil