docs/pyboard: Update name of mounted volume to match code.
docs/pyboard: Update name of mounted volume to match code.

bvernoux/micropython,adafruit/circuitpython,trezor/micropython,bvernoux/micropython,MrSurly/micropython,henriknelson/micropython,pramasoul/micropython,selste/micropython,tobbad/micropython,pramasoul/micropython,tobbad/micropython,MrSurly/micropython,bvernoux/micropython,henriknelson/micropython,pozetroninc/micropython,henriknelson/micropython,trezor/micropython,selste/micropython,MrSurly/micropython,trezor/micropython,selste/micropython,tobbad/micropython,kerneltask/micropython,henriknelson/micropython,adafruit/circuitpython,kerneltask/micropython,tobbad/micropython,adafruit/circuitpython,trezor/micropython,pramasoul/micropython,kerneltask/micropython,kerneltask/micropython,kerneltask/micropython,MrSurly/micropython,selste/micropython,pramasoul/micropython,pozetroninc/micropython,pozetroninc/micropython,selste/micropython,trezor/micropython,bvernoux/micropython,pozetroninc/micropython,adafruit/circuitpython,tobbad/micropython,pramasoul/micropython,adafruit/circuitpython,MrSurly/micropython,adafruit/circuitpython,bvernoux/micropython,pozetroninc/micropython,henriknelson/micropython