[docs] [issue23251] mention in time.sleep() docs that it does not block other Python threads

Martin Panter added the comment: There is also a new sentence about the GIL at the end, but leaving the inbetween lines as they were would verify this ---------- nosy: +vadmium _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue23251> _______________________________________