docs: Add description to example pages. Fixes #4684 (#5125)
docs: Add description to example pages. Fixes #4684 (#5125)


vega/vega-lite,vega/vega-lite,uwdata/vega-lite,uwdata/vega-lite,vega/vega-lite,uwdata/vega-lite,vega/vega-lite,uwdata/vega-lite,uwdata/vega-lite,vega/vega-lite