DOC: Improve DateOffset docstring with constructor and examples (#52431)

[ericzhihuang]

Updates the docstring for the DateOffset class in offsets.pyx.

Changes:

• Added a constructor signature and parameter documentation

This addresses part of issue #52431 (documentation improvements for offset constructors).

[datapythonista]

Thanks for the contribution @ericzhihuang, but I don't understand the changes here. This docstring already has examples and see also sections, you are adding new ones in the middle of the description.

Can you have a look, make sure that the docstring makes sense as a whole, and also check that the CI is happy. I guess it's red because the errors mentioned.

[github-actions]

This pull request is stale because it has been open for thirty days with no activity. Please update and respond to this comment if you're still interested in working on this.

[mroeschke]

Thanks for the pull request, but it appears to have gone stale. If interested in continuing, please merge in the main branch, address any review comments and/or failing tests, and we can reopen.