Produces multi-platform npm package using rollup.js
More specifically to produce "module" in package.json which can be consumed by other projects/builds without requiring them to transpile library code.
{
"module": "my-cool-lib.esm5.js"
}
i.e. my-cool-lib.esm5.js
import {CoolExternalModule} from 'cool-external-library';
//es5 compiled/transpiled code for MyCoolModule that does not need further transpilation.
export MyCoolModule;