Show how to load the library with ESM

[targos]

With node --experimental-wasm-modules, it should be possible to import libsvm from './build.wasm'

[stropitek]

That's only if we are able to build a standalone wasm file. I'm not sure it's possible, because of file io methods that are called to serialize the model.

https://github.com/emscripten-core/emscripten/wiki/WebAssembly-Standalone

[targos]

Node.js supports WASI for i/o