Allow plain arrays.

[mbostock]

Would you consider relaxing this requirement? 😁

Certainly it’s good to encourage the use of a typed array here, say through documentation and examples, but I don’t anticipate the implementation would require that is the input is a typed array (e.g., I don’t think we’d need to call coords.subarray). So it seems reasonable to allow anything array-like as input.

In particular, it’s nice if you already have a flat plain array [x0, y0, x1, y1, …] from some other library, and you aren’t forced to copy that array into a Float64Array to compute the Delaunay triangulation.

[mbostock]

Excellent. I’ve added the requested check.