Fix Document nested tests not supported
*
* Called by the user to register a new test case with the library.
*
+ * Note: Nested addition of tests is not supported. Calling
+ * UtTest_Add from within a test function added using UtTest_Add
+ * will not cause the nested test to execute, and will be
+ * silently ignored.
+ *
* \param Test Main test function to call.
* \param Setup Setup function, called before the test function
* \param Teardown Cleanup function, called after the test function
