Add feedback components 106-130; inert scope, focus return, two-step deploy

text/heading.go

@@ -16,7 +16,7 @@ type HeadingOptions struct {
 
 // Heading is a title with a 1-dot Shade shadow.
 func Heading(c *ui.Context, s string, o HeadingOptions) *ui.Element {
-	level := orDef("Heading Level", o.Level, 1)
+	level := pixel.Or("Heading Level", o.Level, 1)
 	if level > 3 {
 		panic(fmt.Sprintf("text: Heading Level %d outside 1–3", level))
 	}