This project is intended as a minimal example of using Rust to generate WebAssembly that runs in the web browser. There are much better ways to do this if you are more concerned with the end result than with how these technologies work. In particular, if you haven't already looked at wasm-bindgen, you should probably start there. This example is only intended as a demo of the underlying technologies and would need a lot of hardening to be solution worthy of production. See also this blog post.
To add wasm as a compilation target, use rustup:
rustup target add wasm32-unknown-unknown
Then, to compile your file, go:
rustc --target wasm32-unknown-unknown bones.rs
If this works, it'll write a file called bones.wasm in the current directory.
This command is also in build.sh.
In order to load WebAssembly, you need to pass browser CORS checks. The easiest way to do this is to start a local server. You can do this with python3 at the command line by typing:
python3 -m http.server
This works, but it serves the files with cache headers, which can make development confusing.
This project includes a slightly longer Python script under serve.py which adds no-cache to the headers sent by the built-in http server.