add support for visual studio code for the web

[seanbirchall]

Current extension is not available for vs code for the web.

Maybe using webR this could be possible or simpler to do? Does the languageserver R package handle just about everything? I can see that languageserver is currently compiled and available at https://repo.r-wasm.org/.

[eitsupi]

IIUC, this package can't be installed on webR because of dependence packages are not compiled to wasm.