function createPlaceholderCanvas(width, height) {
    const element = document.createElement("canvas");
    const context = element.getContext("2d");
   

    element.width = width;
    element.height = height;

    // Fill in the background
    context.fillStyle = "#aaaaaa";
    context.fillRect(0, 0, element.width, element.height);

    // Place the text
    context.font = "bold 90px sans-serif";
    context.fillStyle = "#333333";
    context.textAlign = "center";
    context.textBaseline = "middle";
    context.fillText(`${width}x${height}`, element.width / 2, element.height / 2);

    return element;
}
Creates a HTML canvas element of the given size.

@param {number} width
@param {number} height
@returns {HTMLCanvasElement}