docs(Demos): updating jupyter-notebook-demo to use sunspots.ipynb, kill process, use eLife theme
docs(Demos): updating jupyter-notebook-demo to use sunspots.ipynb, kill process, use eLife theme

stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila,stencila/stencila