向vega-lite散点图添加回归线

{
  "data": {
    "values": [
      {"x": 1, "y": 2},
      {"x": 2, "y": 4},
      {"x": 3, "y": 6},
      {"x": 4, "y": 8},
      {"x": 5, "y": 10}
    ]
  },
  "layer": [
    {
      "mark": "point",
      "encoding": {
        "x": {"field": "x", "type": "quantitative"},
        "y": {"field": "y", "type": "quantitative"}
      }
    },
    {
      "mark": "line",
      "transform": [
        {"regression": "y", "on": "x"}
      ],
      "encoding": {
        "x": {"field": "x", "type": "quantitative"},
        "y": {"field": "y", "type": "quantitative"}
      }
    }
  ]
}