Prototype a JupyterLite integration

[danielballan]

I have a first pass at this but it's worth doing a fresh review of current best practice.

I think this will be "experimental" for the present, but it's worth including a best-effort attempt at making this work.

[danielballan]

Pixi support: https://prefix.dev/blog/pixi_wasm

[bsipocz]

Has been added in #58