Swift: tweak generated doc comments

Author: redsun82

misc/codegen/templates/ql_class.mustache

@@ -1,7 +1,7 @@
 // generated by {{generator}}
 /**
  * This module provides the generated definition of `{{name}}`.
- * INTERNAL: Do not use. Import the corresponding module under `elements` instead.
+ * INTERNAL: Do not import directly.
  */
 
 private import {{import_prefix}}.Synth
@@ -15,7 +15,8 @@ module Generated {
   {{#doc}}
    * {{.}}
   {{/doc}}
-   * INTERNAL: Do not use. Use the wrapper class under `elements` instead.
+   * INTERNAL: Do not reference the `Generated::{{name}}` class directly.
+   * Use the subclass `{{name}}`, where the following predicates are available.
    */
   class {{name}} extends Synth::T{{name}}{{#bases}}, {{.}}{{/bases}} {
   {{#root}}