Graph example

In server.c, we generate "change" notifications periodically, reporting 512 data points: {"method":"change","params":{"points":[[0,83],[1,99],...

In main.js, we create a uPlot chart instance bound to the div inside the panel

In main.js, we call Dashboard.on('change', function() {...}) to intercept all change notifications, get the points, and then calling chart.setData() to plot received values.