fix issue where lists that didn't start at 1 were not respected (#116)

ansi/listitem.go

@@ -7,12 +7,13 @@ import (
 
 // An ItemElement is used to render items inside a list.
 type ItemElement struct {
+	IsOrdered   bool
 	Enumeration uint
 }
 
 func (e *ItemElement) Render(w io.Writer, ctx RenderContext) error {
 	var el *BaseElement
-	if e.Enumeration > 0 {
+	if e.IsOrdered {
 		el = &BaseElement{
 			Style:  ctx.options.Styles.Enumeration,
 			Prefix: strconv.FormatInt(int64(e.Enumeration), 10),