This commit adds an example of executing the `wasm2asm` tool to generate asm.js
output instead of WebAssembly. This is often useful when supporting older
browsers, such as IE 11, that doesn't have native support for WebAssembly.
Right now Webpack probably has the most mature support for loading wasm modules,
so let's show off how to do that! Additionally this commits hello world as an
example to the repository.