WASM support

Amethyst is beginning to support the Web Assembly (WASM) target, allowing games to run in a web browser.

Currently Amethyst games have only been demonstrated to work on Chrome. This is relatively stable when accessed on Linux; on Windows the browser tab may crash depending on the complexity of the application.

This section covers adding WASM support to a game written with Amethyst. An example of this can be seen in the pong_wasm repository.