The following should allow you to start up and run this code sample.
git clone https://github.com/keatonboyle/case-heatmap.git
cd case-heatmap
npm install
npm run server # Starts a development server. Not yet productionized.Visit http://localhost:3000/case/buckley-v-valeo to see the result.
You should be able to add other case html and citation JSON files into appropriately-named directories underneath assets/cases and see the results.
NOTE: I didn't do much cross-browser testing, things look best on Chrome right now.