Support strikethrough elements

elements.go

@@ -149,6 +149,18 @@ func (tr *TermRenderer) NewElement(node ast.Node, source []byte) Element {
 			},
 		}
 
+	case astext.KindStrikethrough:
+		n := node.(*astext.Strikethrough)
+		s := string(n.Text(source))
+		style := ctx.style[Strikethrough]
+
+		return Element{
+			Renderer: &BaseElement{
+				Token: ctx.SanitizeHTML(s, false),
+				Style: style,
+			},
+		}
+
 	case ast.KindThematicBreak:
 		return Element{
 			Entering: "",

gold.go

@@ -211,7 +211,7 @@ func isChild(node ast.Node) bool {
 
 	// These types are already rendered by their parent
 	switch node.Parent().Kind() {
-	case ast.KindLink, ast.KindImage, ast.KindEmphasis, ast.KindBlockquote, astext.KindTableCell:
+	case ast.KindLink, ast.KindImage, ast.KindEmphasis, astext.KindStrikethrough, ast.KindBlockquote, astext.KindTableCell:
 		return true
 	default:
 		return false

style.go

@@ -25,6 +25,7 @@ const (
 
 	// Text elements
 	Text
+	Strikethrough
 	Emph
 	Strong
 	HorizontalRule
@@ -275,6 +276,8 @@ func keyToType(key string) (StyleType, error) {
 		return H6, nil
 	case "hr":
 		return HorizontalRule, nil
+	case "strikethrough":
+		return Strikethrough, nil
 	case "emph":
 		return Emph, nil
 	case "strong":