add to readme

quad/doc/Unity_notes.md

@@ -14,5 +14,5 @@ as the documentation in [`Unity/docs`](/Unity/docs)
 are nice references
   - Generally, the format is to start `main()` with `UNITY_BEGIN()`, followed by calls to
 `RUN_TEST(test_function)` where `test_function` is a test to run, ended with
-`return UNITY_END()`
-	
+`return UNITY_END()`. Additionally, each `test_function` should be a `void` and call the
+[appropriate asserts](/Unity/docs/UnityAssertionsReference.md).