add a notebook demonstrating _interactive_ notebooks
add a notebook demonstrating _interactive_ notebooks

jpinedaf/pyspeckit,pyspeckit/pyspeckit,pyspeckit/pyspeckit,low-sky/pyspeckit,keflavich/pyspeckit,low-sky/pyspeckit,keflavich/pyspeckit,jpinedaf/pyspeckit,e-koch/pyspeckit,e-koch/pyspeckit