Updating timeseries.offset_aliases links to use :ref: format
During code review on https://github.com/pandas-dev/pandas/pull/57562 it was suggested to update the links from this format

`this link <https://pandas.pydata.org/pandas-docs/stable/user_guide/timeseries.html#offset-aliases>`__.

to this format 

:ref:`this link<timeseries.offset_aliases>`

I found several places where this same link was using this old format, so opened this PR to update them all for consistency. 

- [x] xref https://github.com/pandas-dev/pandas/pull/57562
- [x] [Tests added and passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#writing-tests) if fixing a bug or adding a new feature
- [x] All [code checks passed](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#pre-commit).
- [ ] Added [type annotations](https://pandas.pydata.org/pandas-docs/dev/development/contributing_codebase.html#type-hints) to new arguments/methods/functions.
- [ ] Added an entry in the latest `doc/source/whatsnew/vX.X.X.rst` file if fixing a bug or adding a new feature.

@mroeschke can you take a look at this PR?  based off the suggestion in https://github.com/pandas-dev/pandas/pull/57562 pre-commit.ci autofix

 /preview Website preview of this PR available at: https://pandas.pydata.org/preview/pandas-dev/pandas/57581/