Truncate document after n pages

[thezeus123]

It is often not necessary to transfer the complete document for the title, correspondent and date. This information can usually be found on the first page. For the tags, it can be useful to analyze the complete document.

To save time/costs, an option to transfer only N pages/lines/words/token of a document would be useful.

[paradizelost]

Pretty sure this would be the same as #56