Add a NFC library on adafruit_nRF52_Arduino

[0hotpotman0]

Hi
I base on this core(version 1.0.0) to develop the NFC function, and it works on my nRF52840 board.
This is my link: https://github.com/0hotpotman0/BLE_52840_Core
The link fork from here, but after the library does not work on the new version. could you give some help.

[hathach]

I would like to help but you need to be specific on what is your changes (best to be an PR for code review) and what works and what doesn't work and how to test/reproduce.