func (t *Table) stringMarkdownDash() string {
	r := make(map[string]string)
	for _, name := range t.Fields {
		r[name] = strings.Repeat("-", t.fieldSizes[name]-2)
	}
	return t.rowString(r)
}
func (t *Table) stringMarkdownDash() string {
	r := make(map[string]string)
	for _, name := range t.Fields {
		r[name] = strings.Repeat("-", t.fieldSizes[name]-2)
	}
	return t.rowString(r)
}
// stringMarkdownDash - output dash in middle of table.