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
