✨ NEW: Add `NeedsPerPageBuilder`

[nhatnamnguyengtvthcm]

1. Create a new builder in builde.py called: NeedsPerPageBuilder 2 . run: make-html-fast -> the need_per_page folder will be gened which has seperated the need with same docs_name

[nhatnamnguyengtvthcm]

Some finding, but overall the code looks okay.

However, with Needsfile there is a generic Need-Builder class, which cares about setting everything up the right way. And I think we should use this and just extend it by a function to store the data in a specific way. https://github.com/useblocks/sphinx-needs/blob/master/sphinx_needs/needsfile.py

Your code doubles a lot of functions, like filtering, data preparation, and some magic configurations. That's hard to maintain in the future.

What do you think, is updating Needsfile possible?

I wonder do you want the format of the JSON file generated the same needs.json. should It generate by function in needsfile?

[r-o-b-e-r-t-o]

LGTM. Approved for contribution.