Some inspiration for visualisations

* https://gist.github.com/sj26/7079674
* https://medium.com/ninjaconcept/interactive-dynamic-force-directed-graphs-with-d3-da720c6d7811
* https://github.com/ninjaconcept/d3-force-directed-graph/tree/master/example
* https://itnext.io/d3-force-directed-graph-forces-experiments-for-dummies-20a5682935
* http://bl.ocks.org/sebbacon/6138241 (best)