feat: stick -> dpad in Buttons API

[lajbel]

[dragoncoder047]

here is my suggestion, some would go in the global options like buttons

kaplay({
    buttons: {
        jump: {
            gamepad: ["south", "rstick:up"],
            //                 ^^^^^^^^^^^ virtual buttons available here
            keyboard: ["space"],
        }
    },
    // new entry vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
    sticks: {
        move: {
            gamepad: [
                "lstick",
                {up: "dpad-up", left: "dpad-left",
                 right: "dpad-right", down: "dpad-down"}
            ],
            keyboard: [
                {up: "w", left: "a",
                 right: "d", down: "s"},
                {up: "up", left: "left",
                 right: "right", down: "down"}
                // could also have "wasd" and "arrows" as built-in options here
            ]
        }
    },
})