Request: putting `Field(description="...")` on primitives

[jamesbraza]

I am trying to implement my own driver for the newly released Nvidia nemotron-parse and am finding a lot of page primitives to be unclear:

• PdfPageGeometry -- what is art_bbox, bleed_bbox, and crop_bbox, etc.
• SegmentedPage -- what is textline_cells and char_cells
• TextCell -- what is orig and confidence

The request is, putting Pydantic descriptions with commonly-used data structures will go a long way in helping developers with Docling.

[PeterStaar-IBM]

@jamesbraza Yes, let me add some clarification to these concepts! PR incoming ...