recommend httpx as well as requests in http.client/urllib.request docs

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2021-08-13.06:41:10.763>
labels = ['3.11', '3.10', 'docs']
title = 'recommend httpx as well as requests in http.client/urllib.request docs'
updated_at = <Date 2021-08-14.00:34:24.539>
user = 'https://github.com/graingert'

bugs.python.org fields:

activity = <Date 2021-08-14.00:34:24.539>
actor = 'terry.reedy'
assignee = 'docs@python'
closed = False
closed_date = None
closer = None
components = ['Documentation']
creation = <Date 2021-08-13.06:41:10.763>
creator = 'graingert'
dependencies = []
files = []
hgrepos = []
issue_num = 44908
keywords = []
message_count = 2.0
messages = ['399494', '399576']
nosy_count = 3.0
nosy_names = ['terry.reedy', 'docs@python', 'graingert']
pr_nums = []
priority = 'normal'
resolution = None
stage = None
status = 'open'
superseder = None
type = None
url = 'https://bugs.python.org/issue44908'
versions = ['Python 3.10', 'Python 3.11']