bpo-30754: Document textwrap.dedent blank line behavior. (GH-14469)


* Added documentation for textwrap.dedent behavior.
* Remove an obsolete note about pre-2.5 behavior from the docstring.
(cherry picked from commit eb97b9211e7c99841d6cae8c63893b3525d5a401)

Co-authored-by: tmblweed <tmblweed@users.noreply.github.com>
2 files changed