Add lab 02 - GPIO exercises

website/lab/02/images/button-bounce.png

website/lab/02/images/gpio_ctrl_register.png

website/lab/02/images/gpio_pad_ctrl_1.png

website/lab/02/images/gpio_pad_ctrl_2.png

website/lab/02/images/gpio_pad_registers.png

website/lab/02/images/gpio_status_ctrl.png

website/lab/02/images/international_morse_code.svg

website/lab/02/images/pico-pinout.svg

website/lab/02/images/register.png

website/lab/02/images/reset_registers.png

website/lab/02/images/reset_reset.png

website/lab/02/images/reset_reset_done.png

website/lab/02/images/sio_registers.png

website/lab/02/images/usage.png

website/lab/02/index.mdx