examples: add parsing to the nunchuck example
examples: add parsing to the nunchuck example

E.g. For a pretty idle read (holding and pressing a button):

NunchuckReading {
  joystick_x: 127,
  joystick_y: 128,
  accel_x: 509,
  accel_y: 308,
  accel_z: 656,
  c_button_pressed: false,
  z_button_pressed: true
}

nastevens/rust-i2cdev