titleCfg1.vl

{
    "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
    "data": {
        "url": "https://vega.github.io/vega-lite/data/cars.json"
    },
    "encoding": {
        "x": {
            "field": "Horsepower",
            "type": "quantitative"
        },
        "y": {
            "field": "Miles_per_Gallon",
            "type": "quantitative"
        }
    },
    "height": 200,
    "mark": "circle",
    "title": {
        "subtitle": [
            "A subtitle",
            "also over two lines"
        ],
        "text": [
            "Car",
            "Scatter"
        ]
    },
    "width": 200
}