feature request: shareable link with pre-defined code for webr.r-wasm.org

[pawelru]

(not sure if that's the right repo - feel free to transfer where appropriate)

Something similar to what we have for shinylive when the code compressed and added to the url

https://shinylive.io/r/editor/#code=NobwRAdghgtgpmAXGKAHVA6ASmANGAYwHsIAXOMpMAHTABUALASwGcACAMzilIFcAnOGyIc2LZhACeAGyYA3IazYBzQTwCEbAOpFe0gCZsmpNgCMhqIixZNT0oaSJsGUBW1IMhLWEI5F+bADucKb8APy0YAC+ALpAA