Shattered Pixel Dungeon- v2.5.2, desktop Linux version, github version

I prefer to play on desktop instead of mobile. On desktop, I usually get along fine just clicking to move. But sometimes I feel like using the arrow keys instead.

The arrow keys are fine for going up, down, left, and right. But moving diagonally is very important in this game. What is a comfortable way to configure my controls so that I can comfortably move diagonally? I would prefer a way that does not require the keyboard to have a numpad.

Also, is there any way to hook up a joystick / videogame controller to the desktop and use that for movement instead?

Thank you for your suggestions.