* Added years and months to parse_timedelta
* Added new parse_datetimedelta along with classes for relative dates
* Switched datetime as dt to just datetime for clarity
* Changed to returning relativedelta instead of datetime
* Fixed single char typo
* After some digging, removed min and max from relative delta b/c of https://github.com/dateutil/dateutil/issues/350
* Add dateutil to intersphinx mapping
* Change uppercase D in RelativeDeltaConverter to a lowercase D
* Fix cross-references in docstrings
* Add new class and methods to __all__
* Remove get_relativedelta_converter()
* style
* Fix name of parse_relativedelta test
* more style
* Re-export new class and function in `redbot.core.commands`
Co-authored-by: jack1142 <6032823+jack1142@users.noreply.github.com>
