[docs] [issue34512] Document platform-specific strftime() behavior for non-ASCII format strings

Change by miss-islington <mariatta.wijaya+miss-islington@gmail.com>: ---------- pull_requests: +11134, 11135, 11136, 11137 _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue34512> _______________________________________