Doc: reference Py_REFCNT and Py_SET_REFCNT on the reference counting page

Author: QuakeIV

Doc/c-api/refcounting.rst

@@ -8,7 +8,8 @@ Reference Counting
 ******************
 
 The macros in this section are used for managing reference counts of Python
-objects.
+objects.  Note that :c:macro:`Py_REFCNT` and :c:macro:`Py_SET_REFCNT` are
+documented as a part of :c:type:`PyObject`.
 
 
 .. c:function:: void Py_INCREF(PyObject *o)