zh-TW translation revision suggestion

[winter20161]

In the file "ChatSecureAndroid/res/values-zh-rTW/strings.xml", line 279 is now "使用手冊". I think it would be better to translate the English word "manual" into zh-TW as "手動驗證", which corresponds to its function.

The same file, line 291 is now "為了要驗證對方身分, 打入一個要問聯絡人的問題, 跟對方回答你預想好的正確的回應". I think it would be more proper to revise a few words: "為了驗證對方身分, 輸入一個要問聯絡人的問題, 讓對方回答你預想好的正確答案", which is more in line with the context and also grammar.