[docs] [issue33573] statistics.median does not work with ordinal scale, add doc

[Tal Einat]

Change by Tal Einat <taleinat at gmail.com>:


----------
keywords: +patch
pull_requests: +7209
stage: needs patch -> patch review

_______________________________________
Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue33573>
_______________________________________