Fix godoc for Meta DSL
@@ -27,7 +27,7 @@ import (
//
// var Unused = Type("Unused", func() {
// Attribute("name", String)
-// Meta("type:generate:force", service1, service2)
+// Meta("type:generate:force", "service1", "service2")
// })
//
// - "struct:error:name" identifies the attribute of a result type used to
