Add typescript support

[Razamindset]

Hi there,

I really enjoy using this library—it’s fantastic! However, I noticed it lacks TypeScript support, which makes implementation a bit challenging. While integrating it into my React application, I struggled to identify the available props and understand which parameters can be passed to specific functions.

Adding TypeScript support would be a game-changer for developers like me. This is an amazing project—I can tell because I’ve previously implemented chessgroundjs in React with features like move validation and promotions, and it was quite a challenge!

Looking forward to seeing TypeScript support soon. Thanks for all your hard work!

[Razamindset]

And one more thing I implemented the following and it shows a promotion dialog for no reason

import { NextChessground } from "next-chessground";
import { useEffect, useRef } from "react";

const Board = () => {
  const ref = useRef();

  useEffect(() => {
    if(ref.current){
        ref.current.board.move("d2", "d4")
    }
  
    return () => {
      
    }
  }, [])
  
  return (
    <div className="w-[400px]">
      <NextChessground ref={ref} />;
    </div>
  );
};

export default Board;

Please add more guidelines for contribuiting to this project