docs: update contributing guidelines for drafts (#6559)
docs: update contributing guidelines for drafts (#6559)


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