fix(readme): update information for webpack users
fix(readme): update information for webpack users

changes:
  - clarified situation with webpack
  - added webpack-like example
  - tested result of commonjs transpile and webpack accepts it

addresses:
  - issue #1
doesn't necessarily work with webpack when requiring from node_modules on separate webpack project--need assistance for that

cwadrupldijjit/ng2-parallax,cwadrupldijjit/ng2-parallax