Dockerizing the application

[alexandrascript]

I've dockerized 2048 so that this game can be deployed as a container. I've added both a Dockerfile and Docker Compose file. These will not affect folks who want to just use it locally or deploy it in another manner.

This does not in any way affect game play.

This PR doesn't include the modifications I made to the index content, but you can see the dockerized version working here, deployed to Triton: http://game.alexandra.space/