PageXML support

[JohanVisser97]

Dear Mark,

It's a wonderful tool. To my surprise, correcting Transkribus transcriptions (17C Dutch!) with Claude 3.5 works impressive. However, transcribing from scratch with GPT-4o doesn't render any usable results on my stuff. I'm wondering if you have any future plans to add support for pageXML files, so one can keep the relation between image and text. That would also enable reimporting the corrected transcriptions into Transkribus again.
On the left, corrected with Claude. On the right the original Transkribus transcription.