worksheet: Create a worksheet object
In rsheets/linen: Spreadsheet Data Structures

Create a worksheet object

1	worksheet(name, cols, rows, cells, merged, view, comments, workbook)

`name`	The name of the worksheet
`cols`	columns
`rows`	rows
`cells`	A `tbl_df`, created by `cells`.
`merged`	A list of `cell_limits` objects indicating merged cellls. Can be an empty list if there are no merged cells.
`view`	view
`comments`	comments
`workbook`	A workbook object.