[docs] [issue43283] IDLE: Explain print slowness and speedup method

Change by miss-islington <mariatta.wijaya+miss-islington@gmail.com>: ---------- pull_requests: +23415 pull_request: https://github.com/python/cpython/pull/24631 _______________________________________ Python tracker <report@bugs.python.org> <https://bugs.python.org/issue43283> _______________________________________