Wrapper element containing ALL panel containers. The combined maidr
attribute must be set on this element (not on the individual panel
containers): root.setAttribute('maidr', JSON.stringify(maidr)).
OptionalidUnique ID for the MAIDR instance. Defaults to the root element's id.
OptionaltitleFigure-level title announced when the figure receives focus.
OptionallayoutGrid shape for a FLAT panels array, chunked row-major. columns wins
when both are given; with only rows, columns = ceil(n / rows). Ignored
when panels is already a 2D array.
Options accepted by createMaidrFromGoogleCharts.