Expand section explaining role of the backend
Expand section explaining role of the backend

Based on @ebruchez explanation in Gitter: https://gitter.im/japgolly/scalajs-react?at=5668e4d4c4b3d2a52a6b3d04
japgolly/scalajs-react,matthughes/scalajs-react,japgolly/scalajs-react,japgolly/scalajs-react,7thsense/scalajs-react,7thsense/scalajs-react,zlangbert/scalajs-react,zlangbert/scalajs-react,matthughes/scalajs-react,matthughes/scalajs-react,japgolly/scalajs-react,zlangbert/scalajs-react,7thsense/scalajs-react