WASM assetsys example

[konsumer]

I dunno if it's useful for anyone, but I wanted to see if I could load files with the same code on native/wasm (via emscripten) and it worked great! Here is the deployed example. I had some issues with physfs in emscripten, and didn't need all the containers it supported (so I disabled all but zip) and assetsys was just a way better fit. Would you like a PR for the example, or a link in README?

Unrelated: I love this collection of headers! assetsys is very simple to use, and works great, and everything else is mega-useful. Keep up the good work!