PrintNC GRBLHAL2000 EST firmware

This is a prebuilt image for the GRBLHAL2000 board that is used in the PrintNC EST project. It works with any GRBLHAL2000 board. It has the updated VFD and Keypad plugins from Expatria, as well as the RGB plugin from 5ocworkshop. The following settings are enabled in my_machine.h:

#define USB_SERIAL_CDC 1
#define VFD_ENABLE -1
#define MODBUS_ENABLE 1
#define ETHERNET_ENABLE 1
#define KEYPAD_ENABLE 1
#define RGB_ENABLE 1
#define DUAL_SPINDLE 1
#define Y_GANGED 1
#define Y_AUTO_SQUARE 1