Turns a 'gt' table into a range of cells in an 'openxlsx2' workbook, keeping the heading, column spanners, row groups, stub, summary rows, footnotes and the styling set through 'gt'. Numbers stay numbers wherever a spreadsheet number format can reproduce what 'gt' shows. A second entry point does the same for a plain HTML table, so output from other table packages can be written to a worksheet as well; that path needs nothing beyond 'openxlsx2'.