[docs] [issue38413] Remove or change "Multithreading" section

Change by David Kernan <davidsmurf@gmail.com>: ---------- keywords: +patch pull_requests: +16262 stage: -> patch review pull_request: https://github.com/python/cpython/pull/16678 _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue38413> _______________________________________