Clarify that PyErr_NewException creates an exception *class*, not instance.

Doc/c-api/exceptions.rst

@@ -352,10 +352,10 @@ is a separate error indicator for each thread.
 
 .. cfunction:: PyObject* PyErr_NewException(char *name, PyObject *base, PyObject *dict)
 
-   This utility function creates and returns a new exception object. The *name*
+   This utility function creates and returns a new exception class. The *name*
    argument must be the name of the new exception, a C string of the form
-   ``module.class``.  The *base* and *dict* arguments are normally *NULL*.  This
-   creates a class object derived from :exc:`Exception` (accessible in C as
+   ``module.classname``.  The *base* and *dict* arguments are normally *NULL*.
+   This creates a class object derived from :exc:`Exception` (accessible in C as
    :cdata:`PyExc_Exception`).
 
    The :attr:`__module__` attribute of the new class is set to the first part (up