Doc: fix SA01 errors for as_ordered and as_unordered

[jordan-d-murphy]

All SA01 Errors resolved in the following cases:

1. scripts/validate_docstrings.py --format=actions --errors=SA01 pandas.Categorical.as_ordered
2. scripts/validate_docstrings.py --format=actions --errors=SA01 pandas.Categorical.as_unordered
3. scripts/validate_docstrings.py --format=actions --errors=SA01 pandas.CategoricalIndex.as_ordered
4. scripts/validate_docstrings.py --format=actions --errors=SA01 pandas.CategoricalIndex.as_unordered
5. scripts/validate_docstrings.py --format=actions --errors=SA01 pandas.Series.cat.as_ordered
6. scripts/validate_docstrings.py --format=actions --errors=SA01 pandas.Series.cat.as_unordered

• xref DOC: fix SA01 errors in docstrings  #57417
• Tests added and passed if fixing a bug or adding a new feature
• All code checks passed.
• Added type annotations 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]

Thanks @jordan-d-murphy