DOC: Timestamp EX01 errors (pandas-dev#37904)

* SS01 errors fixed

* trailing-whitespace error fixed

* added coded to code_checks.sh script

* fixed docstrings consistency

* mistaken file

* trailing-whitespace typo

* Example section for ceil method

* Added example section for ceil, floor and round

* example section added to methods day_name, month_name, fromordinal, utcfromtimestamp, fromtimestamp, combine. Typos in ceil, round, floor corrected

* trailing whitespace

* typo in floor method

* added example section for method normalize

* typo

* recommendations from pull request review

* typo

* revert changes. to be addressed in another PR

* Added NaT examples in nattype and timestamp docstrings where needed.

* trigger GitHub actions

* added missing ( in docstring examples

* added missing ( in docstring example

Co-authored-by: lucasrodes <lucasrodesg@gmail.com>