Add concrete examples to os.path documentation

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2020-10-05.16:06:07.462>
labels = ['type-feature', 'docs']
title = 'Add concrete examples to os.path documentation'
updated_at = <Date 2021-08-05.19:37:30.280>
user = 'https://github.com/theacodes'

bugs.python.org fields:

activity = <Date 2021-08-05.19:37:30.280>
actor = 'jack__d'
assignee = 'docs@python'
closed = False
closed_date = None
closer = None
components = ['Documentation']
creation = <Date 2020-10-05.16:06:07.462>
creator = 'theacodes'
dependencies = []
files = []
hgrepos = []
issue_num = 41946
keywords = []
message_count = 5.0
messages = ['378043', '398912', '399025', '399027', '399032']
nosy_count = 5.0
nosy_names = ['rhettinger', 'docs@python', 'theacodes', 'andrei.avk', 'jack__d']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = 'enhancement'
url = 'https://bugs.python.org/issue41946'
versions = []