Make comments more useful

category.go

@@ -13,7 +13,8 @@ type Category struct {
 	Label  string `xml:"label,attr,omitempty"`  // Must be unescaped
 }
 
-// NewCategory creates a new Category. It returns a *Category.
+// NewCategory creates a new Category. It takes in a string term and returns a
+// *Category.
 func NewCategory(term string) *Category {
 	return &Category{
 		CommonAttributes: NewCommonAttributes(),