docs: Update SparkPI README
docs: Update SparkPI README

The instructions now use Quilt.js instead of the lisp, and furthermore shows
the right console output format.

stevenlin598/quilt,quilt/quilt,NetSys/quilt,ejj/quilt-dev,PenguinToast/quilt,LuiseV/quilt,LuiseV/quilt,stevenlin598/quilt,PenguinToast/quilt,stevenlin598/quilt,PenguinToast/quilt,mmussomele/quilt,kklin/quilt,ejj/quilt-dev,NetSys/quilt,kelda/kelda,kklin/quilt,kklin/quilt,NetSys/quilt,mmussomele/quilt,quilt/quilt,tejasmanohar/quilt,kelda/kelda,quilt/quilt,mmussomele/quilt,tejasmanohar/quilt,mmussomele/quilt,mmussomele/quilt,LuiseV/quilt,kayousterhout/quilt,stevenlin598/quilt,PenguinToast/quilt,quilt/quilt,NetSys/quilt,ejj/quilt-dev,kklin/kelda,kayousterhout/quilt,mmussomele/quilt,kklin/kelda,kayousterhout/quilt,stevenlin598/quilt,stevenlin598/quilt,kelda/kelda,LuiseV/quilt,tejasmanohar/quilt,kklin/kelda,kklin/quilt,PenguinToast/quilt,kayousterhout/quilt,ejj/quilt-dev,kklin/kelda,kelda/kelda,NetSys/quilt,tejasmanohar/quilt,LuiseV/quilt