run-wasm

This provides an xtask that makes it trivial to run web-based examples.

It relies on cargo-run-wasm to run the wasm-bindgen machinery, generate HTML files and all of that good stuff. This is a temporary solution while we're in the process of building our own xtask tools.

You can try it e.g. with the standalone re_renderer demo:

cargo run-wasm --example 2d