Rename scale.ts's `ordinalToContinuousType` to `discreteToContinuousType`
Rename scale.ts's `ordinalToContinuousType` to `discreteToContinuousType`

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