Adds labels to vega charts rendered using SVG. I wrote this as there is no easy built-in support for labels in vega-lite at this time, and full vega is too complicated for others who may be creating charts in my organisation. This supports most kinds of chart.
Assuming we have a Label field in our chart data points:
vega.embed(selector, chart, options, function(error, result) {
vegaLabels.addLabels(result.view, "Label");
}
