mkXultra

@chaojiang06 @astromaddie Hi I implented this feature. https://github.com/yihong0618/bilingual_book_maker/pull/420 @yihong0618 pls check this PR

@yihong0618 @vizmoe I'm working on it. its almost done. https://github.com/yihong0618/bilingual_book_maker/pull/423

@yihong0618 I'm done. plz review it if you have time.