cellOptionsOverride

pub fn cellOptionsOverride(self: *const Borders, cell_opts: CellOptions) Borders {
        return .{
            .external = self.external,
            .internal = self.internal,
            .num_cols = self.num_cols,
            .num_rows = self.num_rows,
            .cell_opts = self.cell_opts.override(cell_opts),
            .opts = self.opts,
        };
    }