Added link to Vega-Lite Graphics Companion (#4615)
Added link to Vega-Lite Graphics Companion (#4615)

Included Trafford Data Lab's Vega-Lite Graphics Companion to the list of Community Examples
uwdata/vega-lite,uwdata/vega-lite,uwdata/vega-lite,vega/vega-lite,vega/vega-lite,vega/vega-lite,uwdata/vega-lite,vega/vega-lite,vega/vega-lite,uwdata/vega-lite