Fix hid.py example.
#
# Add the following script to boot.py:
#
-##import pyb (UNCOMMENT THIS LINE!)
+##import pyb #(UNCOMMENT THIS LINE!)
##pyb.usb_mode('VCP+HID') # serial device + mouse (UNCOMMENT THIS LINE!)
##pyb.usb_mode('VCP+MSC') # serial device + storage device (default)
##pyb.usb_mode('VCP+HID', hid=pyb.hid_keyboard) # serial device + keyboard
