Multi-line time axis for ordinal time scales

[mbostock]

If the interval option is used in conjunction with an ordinal scale, we should be able to use the nice multi-line time axis to choose appropriate ticks and tick format automatically. For example, I should be able to drop the ticks and tickFormat option here and get the same result:

Plot.barY(
  aapl,
  Plot.groupX(
    { y: "median", title: "min" },
    { title: "Date", x: "Date", y: "Close" }
  )
).plot({
  x: {
    interval: "month",
    tickFormat: "%Y",
    ticks: d3.utcYears(...d3.extent(aapl, (d) => d.Date))
  }
})

Related #932.