[easy doc] Document os.rename() behavior on Windows when src and dst are on different filesystems

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2016-10-04.13:42:32.460>
labels = ['easy', '3.8', '3.9', '3.10', 'type-feature', 'OS-windows', 'docs']
title = '[easy doc] Document os.rename() behavior on Windows when src and dst are on different filesystems'
updated_at = <Date 2021-08-02.13:03:11.787>
user = 'https://bugs.python.org/stephan'

bugs.python.org fields:

activity = <Date 2021-08-02.13:03:11.787>
actor = 'vstinner'
assignee = 'docs@python'
closed = False
closed_date = None
closer = None
components = ['Documentation', 'Windows']
creation = <Date 2016-10-04.13:42:32.460>
creator = 'stephan'
dependencies = []
files = ['50180']
hgrepos = []
issue_num = 28356
keywords = ['patch', 'easy', 'newcomer friendly']
message_count = 13.0
messages = ['278035', '278036', '278038', '278040', '278041', '278048', '278113', '387667', '388283', '388295', '388297', '388322', '398201']
nosy_count = 9.0
nosy_names = ['paul.moore', 'tim.golden', 'docs@python', 'zach.ware', 'eryksun', 'steve.dower', 'stephan', 'scienidlex', 'rhyn0']
pr_nums = ['27376']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue28356'
versions = ['Python 3.8', 'Python 3.9', 'Python 3.10']