[REQUEST] Add the option to change D-Pad as Keyboard keypad

[gustavoalara]

When you use the OpenFire lightgun in mouse\keyboard mode the D-Pad is assigned to the gamepad\joystick part (like the analog stick). However, emulators like Teknoparrot when configuring a lightgun game in raw-input mode doesn't detect the D-Pad or analog Stick and you can't assign these buttons in the game input.

So, when in mouse mode at least D-Pad must be assigned to the up, down, right and left keys (if the stick could be assigned too, will be wonderful)

[SeongGino]

In the short term, you can always build the firmware from source, changing the contents of LightgunButtons::ButtonDesc[] in SamcoEnhanced.ino to your preferred controls; in this case, just the entries for bGunUp/bGunDown/bGunLeft/bGunRight. Refer to COMPILING.md for info on the manual build process.

In the long term, this is where button function remapping would come in handy so it can be configured from the App.

Analog-to-digital will be handled in its own PR, as it's polled separately from the rest of the digital inputs so it would need its own decision tree.

[gustavoalara]

Thank you @SeongGino

First approach is the way I did, but as you said the button function remapping would be a nice feature to customize the keys people use in their games/emulators without the need of rebuild the firmware