Include prebuilt js for browsers in npm packages

[Mourdraug]

Including prebuilt js in npm packages would really simplify installation of this library when using bundlers other than browserify.
Right now adding it to Angular project through npm is a real pain, theorethically we could use brfs, but latest Angular CLI have ng eject command disabled, and at this point it's easier to just add file manually and update it by hand which requires keeping a copy of library in repo.

Meanwhile pdfmake which wraps pdfkit suffers from same issue outside browserify but since it includes prebuilt js we can import it like import pdfMake from 'pdfmake/build/pdfmake.js';