DOC: Typo in pandas.tseries.offset
### 

- [X] I have checked that the issue still exists on the latest versions of the docs on `master` [here](https://pandas.pydata.org/docs/dev/)


### Location of the documentation

https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.tseries.offsets.BYearEnd.html

### Documentation problem

A “s” is missing in the word “offset” `from pandas.tseries.offset import BYearEnd`



### Suggested fix for documentation

`from pandas.tseries.offsets import BYearEnd`
