[USBMapping] Link to incomplete docu

Please stop and read this carefully. Otherwise your issue will be left **unanswered** and **closed**.

We require the following for guide issues:

* Guide(s) in question
USB MAPPING

* Link to page(s) with the issue
https://dortania.github.io/OpenCore-Post-Install/usb/intel-mapping/intel.html

* Clearly explain the issue(s) with the page(s) (if there is a visual issue, a screenshot is required)
The page recommends to read a docu to which it links:
https://github.com/corpnewt/USBMap
but that docu does not include a real how-to, but "only" a history lesson (which is cool and informative). A newbie like me is now totally lost and discouraged - having come so far, and suddenly: nothing. IMO this is a no-go and really needs to be fixed ASAP.

* Include possible fixes
I cannot offer a fix, since I am not familiar with that subject. (I am learning it.)

In the "Issue" guideline you mention:
"Note we only maintain Dortania guides, so please do not open issues for other guides."
Hmmm... guess this is one that does not really go along with that statement... :-)

Any chance to provide the promised re-write?