translate chinese strings:

    # game/scripts/characters/tonks/requests.rpy:3
    old "Detention with Tonks."
    new "留堂辅导."
    # game/scripts/characters/tonks/requests.rpy:22
    old "Hands-on lessons!"
    new "实践课!"
    # game/scripts/characters/tonks/requests.rpy:41
    old "Oral practice!"
    new "口头练习!"