I am a noob game developer trying to make HTML5 games with JS and canvas. How do I do this with multiple files? I already uploaded to itch my first game pong which I originally wrote with node as a web server to not get CORS errors. When uploading to itch I had to make all the code in one js file. On my next game flappy bird that I am almost done with I just need to implement restart all the code is really messy because everything is in one file. How can I separate all the code into multiple files and have it work in itch.io?