DOC: reduce API docs for offset aliases

[jorisvandenbossche]

Test to see if this works with sphinx

[jbrockmendel]

Nice, there are some other aliases we could do the same for if this works.

Also some methods/properties that dont need to be advertised, e.g. __call__

[jorisvandenbossche]

Yeah, first need to see if it works ;)
(locally it did, but I would actually expect to need to edit the BDay docstring to ensure it lists no methods/attributes, similar as eg the docstring of DatetimeArray)

[jorisvandenbossche]

It seems to work.

Can you say which are the aliases? Just the ones here?

pandas/pandas/_libs/tslibs/offsets.pyx

Lines 3487 to 3494 in 5239cfa

	BDay = BusinessDay
	BMonthEnd = BusinessMonthEnd
	BMonthBegin = BusinessMonthBegin
	CBMonthEnd = CustomBusinessMonthEnd
	CBMonthBegin = CustomBusinessMonthBegin
	CDay = CustomBusinessDay

[jbrockmendel]

I think thats all of them, yes.