DOC: Add examples to frequency classes and methods (#48011)
DOC: Add examples to frequency classes and methods (#48011)

* Add examples to offsets

* Finish examples for offsets

* Finish examples for offsets

* Undo API removals, fix failures

* Address review
datapythonista/pandas,pandas-dev/pandas,pandas-dev/pandas,datapythonista/pandas,pandas-dev/pandas,pandas-dev/pandas,datapythonista/pandas,datapythonista/pandas