RFC: Initial commit of Elmo's World

I am not sure how serious to take myself here, but having seen a React project up close, I do long for the simplicity of Elm. My confidence in what the code does (and more importantly does not) is significantly larger and the toolchain is simple (one binary for the compiler and another one for the formatter).

It maybe that we would miss some fundamental functionality from either the React or the NPM ecosystem which I just do not know yet. Or the risk of using a niche language is just too high. However, the experience of having written this was so much nicer than reading through the NPM/React/Typescript setup that I wanted to at least propose this.