Make comments more useful

plainText.go

@@ -13,7 +13,8 @@ type PlainText struct {
 // isText checks whether the PlainText is a Text. It returns a bool.
 func (p *PlainText) isText() bool { return true }
 
-// newPlainText creates a new PlainText. It returns a *PlainText.
+// newPlainText creates a new PlainText. It takes in the strings textType and
+// content and returns a *PlainText.
 func newPlainText(textType, content string) *PlainText {
 	return &PlainText{
 		CommonAttributes: NewCommonAttributes(),