ulab/__init__.rst: fix attribute name; uint8 -> uint16
ulab/__init__.rst: fix attribute name; uint8 -> uint16

adafruit/circuitpython,adafruit/micropython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/circuitpython,adafruit/micropython,adafruit/micropython,adafruit/micropython,adafruit/micropython