HTML port

[sjehuda]

Port Assault Cube to HTML as done with Quake III and wipEout

• https://github.com/WofWca/quake3.xdc
• https://phoboslab.org/log/2023/08/rewriting-wipeout

It would also allow to port AssaultCube to WebXDC, and play it ovver DeltaChat and XMPP which both support WebXDC.