Create a GitHub pages site with the bevy_ggrs example

[johanhelsing]

Resolves #212

Code largely borrowed from bevy-shell-template

Supersedes: #244

[johanhelsing]

Trying to see if I can get the deploy job to pass...

This is rather unhelpful:

[johanhelsing]

Okay, it's deploying now, but seems I glossed over the issue with the panic:

panicked at 'Cannot find element: #bevy_ggrs_example.', /home/runner/.cargo/registry/src/index.crates.io-6f17d22bba15001f/bevy_winit-0.11.2/src/winit_windows.rs:137:21

[johanhelsing]

Should also check why the artifact is 85 mb, maybe we're not building release builds?

[johanhelsing]

Alternatively, we can do this with just wasm-opt/wasm-pack, and we can use the same launcher I use for all the embeds on my blog:

https://johanhelsing.studio/bevy-embed?app=extreme_4

Should allow the example to stay simple stupid (no trunk/yew or anything), and no hacks for canvas elements.

[simbleau]

Should also check why the artifact is 85 mb, maybe we're not building release builds?

That would definitely be the case. My builds are usually <10MB in release mode when I deploy my entire game (which includes matchbox).

[johanhelsing]

Closing in favor of #335