Sentence Boundaries missing in Dataset: xtreme / udpos
Hi,

This is a known issue. More info on this issue can be found in #2061. If you are looking for an open-source contribution, there are step-by-step instructions in the linked issue that you can follow to fix it. Closed by #2466.
I was browsing through annotation guidelines, as suggested by the datasets introduction.

The guidlines saids "There must be exactly one blank line after every sentence, including the last sentence in the file. Empty sentences are not allowed." in the [Sentence Boundaries and Comments section](https://universaldependencies.org/format.html#sentence-boundaries-and-comments)

But the sentence boundaries seems not to be represented by huggingface datasets features well. I found out that multiple sentence are concatenated together as a 1D array, without any delimiter.

PAN-x, which is another token classification subset from xtreme do represent the sentence boundary using a 2D array.

You may compare in PAN-x.en and udpos.English in the explorer:
 https://huggingface.co/datasets/viewer/?dataset=xtreme