Added NAU7802 library

Author: tekktrik

.gitmodules

@@ -947,3 +947,6 @@
 [submodule "libraries/helpers/wave"]
 	path = libraries/helpers/wave
 	url = https://github.com/adafruit/Adafruit_CircuitPython_wave.git
+[submodule "libraries/drivers/nau7802"]
+	path = libraries/drivers/nau7802
+	url = https://github.com/adafruit/CircuitPython_NAU7802.git

docs/drivers.rst

@@ -490,6 +490,7 @@ These provide functionality similar to ``analogio``, ``digitalio``, ``pulseio``,
     MCP4725 Digital-to-Analog Converter <https://docs.circuitpython.org/projects/mcp4725/en/latest/>
     MCP4728 4-Channel, 12-bit Digital-to-Analog Converter <https://docs.circuitpython.org/projects/mcp4728/en/latest/>
     MPR121 Capacitive Touch Sensor <https://docs.circuitpython.org/projects/mpr121/en/latest/>
+    NAU7802 24-Bit ADC <https://docs.circuitpython.org/projects/nau7802/en/latest/>
     PCA9685 16 x 12-bit PWM Driver <https://docs.circuitpython.org/projects/pca9685/en/latest/>
     PCF8574 GPIO Expander <https://docs.circuitpython.org/projects/pcf8574/en/latest/>
     PCF8575 GPIO Expander <https://docs.circuitpython.org/projects/pcf8575/en/latest/>