Tweak wording about Fraction and Decimal (GH-10904)

Doc/library/stdtypes.rst

@@ -220,8 +220,8 @@ numbers for the machine on which your program is running is available
 in :data:`sys.float_info`.  Complex numbers have a real and imaginary
 part, which are each a floating point number.  To extract these parts
 from a complex number *z*, use ``z.real`` and ``z.imag``. (The standard
-library includes additional numeric types, :mod:`fractions` that hold
-rationals, and :mod:`decimal` that hold floating-point numbers with
+library includes the additional numeric types :mod:`fractions.Fraction`, for
+rationals, and :mod:`decimal.Decimal`, for floating-point numbers with
 user-definable precision.)
 
 .. index::