DOC: fix PR09,PR08 doc string errors in Timestamp, NaT, Timedelta class
This fixes PR09,PR08 errors in Timestamp, NaT, Timedelta classes

Example:

```
pandas.Timestamp.ceil: Parameter "ambiguous" description should finish with "."
pandas.Timestamp.ceil: Parameter "nonexistent" description should finish with "."
pandas.Timestamp.day_name: Parameter "locale" description should finish with "."
pandas.Timestamp.floor: Parameter "ambiguous" description should finish with "."
pandas.Timestamp.floor: Parameter "nonexistent" description should finish with "."
pandas.Timestamp.fromordinal: Parameter "ordinal" description should finish with "."
pandas.Timestamp.fromordinal: Parameter "freq" description should finish with "."
pandas.Timestamp.month_name: Parameter "locale" description should finish with "."
pandas.Timestamp.now: Parameter "tz" description should finish with "."
pandas.Timestamp.round: Parameter "ambiguous" description should finish with "."
pandas.Timestamp.round: Parameter "nonexistent" description should finish with "."
pandas.Timestamp.today: Parameter "tz" description should finish with "."
pandas.Timestamp.tz_localize: Parameter "ambiguous" description should finish with "."
pandas.Timestamp.tz_localize: Parameter "nonexistent" description should finish with "."
pandas.Timestamp.tz_localize: Parameter "errors" description should finish with "."
```

closes #28673

- [x] closes #xxxx
- [x] tests added / passed

looks like the tests are failing due to:

```
compare = (<class 'pandas._libs.tslibs.timestamps.Timestamp'>, 'ceil')

    @pytest.mark.parametrize(
        "compare",
        (
            _get_overlap_public_nat_methods(Timestamp, True)
            + _get_overlap_public_nat_methods(Timedelta, True)
        ),
    )
    def test_nat_doc_strings(compare):
        # see gh-17327
        #
        # The docstrings for overlapping methods should match.
        klass, method = compare
        klass_doc = getattr(klass, method).__doc__
```

which i am assuming means i will also need to edit the Timedelta class  adding NaT, Timedelta class since it looks like I'll have to fix those too to get it to past the tests confirmed that this fixes PR09 for `Timedelta,Timestamp,NaT` classes:

```
./scripts/validate_docstrings.py --errors=PR09,PR08 | grep -E "Timedelta\.|Timestamp\.|NaT\."
``` this is related to #27977 and #28602 (adding for visibility) sorry about re-adding all the commits @datapythonista ; something was screwed up with how I had my local branch set up. should be fixed now. apologies, i am a little confused on this one and cant figure out what im doing wrong. I ran:

```
git checkout PR09-Timestamp-fix
git fetch upstream
git merge upstream/master
```

but this adds more commits into the PR. let me read up on github docs and figure out what im doing and then ill take a another stab at opening a PR 