Support/documentation for multiple entry points

[MIJOTHY]

It's not too clear how (if) support for bundling multiple entry-points can be done with purs-loader. Currently for each entry point, it chucks all the ps in, leading to separate ps bundles being given a lot of unnecessary code that isn't present when just a single entrypoint is specified. This would be quite a nice feature.

[ethul]

Thanks for this. I will have to spend some time to see if something like this could be supported. However, if you are willing to take a look, a documentation or code update PR would be most welcome for it!