bpo-30052: Link `bytes` & `bytearray` to stdtypes not functions  (GH-1271)

Builtin container types have two potential link targets in the docs:

- their entry in the list of builtin callables
- their type documentation

This change brings `bytes` and `bytearray` into line with other
container types by having cross-references default to linking to
their type documentation, rather than their builtin callable entry.
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 058fa90..4b49bfd 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -320,9 +320,9 @@
 
          A bytes object is an immutable array.  The items are 8-bit bytes,
          represented by integers in the range 0 <= x < 256.  Bytes literals
-         (like ``b'abc'``) and the built-in function :func:`bytes` can be used to
-         construct bytes objects.  Also, bytes objects can be decoded to strings
-         via the :meth:`~bytes.decode` method.
+         (like ``b'abc'``) and the built-in :func:`bytes()` constructor
+         can be used to create bytes objects.  Also, bytes objects can be
+         decoded to strings via the :meth:`~bytes.decode` method.
 
    Mutable sequences
       .. index::
@@ -349,9 +349,9 @@
          .. index:: bytearray
 
          A bytearray object is a mutable array. They are created by the built-in
-         :func:`bytearray` constructor.  Aside from being mutable (and hence
-         unhashable), byte arrays otherwise provide the same interface and
-         functionality as immutable bytes objects.
+         :func:`bytearray` constructor.  Aside from being mutable
+         (and hence unhashable), byte arrays otherwise provide the same interface
+         and functionality as immutable :class:`bytes` objects.
 
       .. index:: module: array
 
@@ -1253,8 +1253,8 @@
 
    .. index:: builtin: bytes
 
-   Called by :func:`bytes` to compute a byte-string representation of an
-   object. This should return a ``bytes`` object.
+   Called by :ref:`bytes <func-bytes>` to compute a byte-string representation
+   of an object. This should return a :class:`bytes` object.
 
    .. index::
       single: string; __format__() (object method)