To do:

• change x axis value to readable time
• add brush to zoom. Idea from https://observablehq.com/@294bb65f21bfa9db/zoom-and-brush-poc and https://communities.sas.com/t5/SAS-Communities-Library/Adding-brush-and-zoom-events-to-a-D3-js-streamgraph-in-SAS/ta-p/513331