[docs] [issue17700] Update Curses HOWTO for 3.4

STINNER Victor added the comment: window.get_wch() and curses.unget_wch(ch) should be used instead of window.getch() and curses.ungetch(ch), when available. They work much better with non-ASCII characters. ---------- nosy: +haypo _______________________________________ Python tracker <report@bugs.python.org> <http://bugs.python.org/issue17700> _______________________________________