Clarify a couple of things in the docs:
1) you must return flat names (no slashes)
2) g_strfreev() will be called on the result
3) a benefit of using the DISPATCH_TO_UNENUMERATED flag
*
* The type of the @enumerate function in #GDBusSubtreeVTable.
*
+ * This function is called when generating introspection data and also
+ * when preparing to dispatch incoming messages in the event that the
+ * %G_DBUS_SUBTREE_FLAGS_DISPATCH_TO_UNENUMERATED_NODES flag is not
+ * specified (ie: to verify that the object path is valid).
+ *
+ * Hierarchies are not supported; the items that you return should not
+ * contain the '/' character.
+ *
+ * The return value will be freed with g_strfreev().
+ *
* Returns: A newly allocated array of strings for node names that are children of @object_path.
*
* Since: 2.26