v0.21.1 — Map direct colors

Added

• Map direct colors — color a map with the same trailing-token idiom used
  everywhere else in dgmo, no tag group required:
  • poi Austin red sets a POI's marker fill directly (wins over a tag color
    and the default orange).
  • Texas red (or California blue value: 92) paints a region a flat
    categorical highlight that ignores the active colouring dimension and adds
    no legend entry — the lightweight "make this one stand out" escape hatch.
  • region-metric Sales ($M) blue sets the choropleth ramp hue (was always
    red). A place literally named for a color keeps it via capitalization
    (poi Orange).