Better declaration for wix-window.getBoundingRect() return type

The current declaration is:

`type WindowSizeInfo = {
        window: any
        document: any;
        scroll: any;
    }; `

The correct declaration is:
`type WindowSizeInfo = {
	document: {height: number, width: number};
	scroll: {x: number, y: number};
	window: {height: number, width: number};
};`