DOC: fix PR09,PR08 errors for pandas.Timestamp
Alright, trying this again. 

Note: for `Timestamp.tz_localize` , the `deprecated:: 0.24.0` was in the wrong place. the indentation implied it was only deprecating the `coerce` argument of the `errors` parameter, but if you read both of the arguments for `errors`, it implies the entire parameter is deprecated in favor of `nonexistent` (added in 0.24.0)

Regarding the length of this PR, it also involved editing the NaT type class and Timedelta class. This is because there is a validation which enforces all of these classes to have the same docstrings.

- [x] closes #28673
- [x] tests added / passed