`Mark` type definitions are missing public (?) API

[mwaibel-go]

According to https://observablehq.com/@observablehq/read-channels-initialized-by-a-plot-mark we can access the plotted data as transformed by Plot. (I hope this API hasn’t become internal since.)

The initialize function, however, is missing from the type definitions:

plot/src/mark.d.ts

Lines 483 to 492 in 356f579

	/** The abstract base class for Mark implementations. */
	export class Mark {
	constructor(data?: Data, channels?: Record<string, Channel>, options?: MarkOptions, defaults?: MarkOptions);
	/**
	* Renders a new plot, prepending this mark as the first element of **marks**
	* of the specified *options*, and returns the corresponding SVG element, or
	* an HTML figure element if a caption or legend is requested.
	*/
	plot: typeof plot;
	}

I also couldn’t find this in the documentation.