[issue46439] Clarify urllib.request.add_header documentation

[Ashwin Ramaswami]

Change by Ashwin Ramaswami <aramaswamis at gmail.com>:


----------
keywords: +patch
pull_requests: +28904
stage:  -> patch review
pull_request: https://github.com/python/cpython/pull/30708

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue46439>
_______________________________________