@sheetwrite/coretype
How a column's cells are typed, parsed, and rendered: text verbatim, number
via its numberFormat, date as an Excel-style serial (see date-serial.ts)
rendered by a date numberFormat, and currency as a plain number rendered by
a currency numberFormat (e.g. $#,##0.00).
Declaration
export type CellFormat = "text" | "number" | "date" | "currency";