Move placement of memoryview generic note

Previous placement was at the end of the main docstring, which is
consistent with other types but places it after a section on various
methods (which makes it read somewhat inconsistently). Moving it up
helps resolve.

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

Author: sirosen

Doc/library/stdtypes.rst

@@ -4592,6 +4592,8 @@ copying.
    types such as :class:`bytes` and :class:`bytearray`, an element is a single
    byte, but other types such as :class:`array.array` may have bigger elements.
 
+   memoryviews are :ref:`generic <generics>` over the type of their underlying data.
+
    ``len(view)`` is equal to the length of :meth:`~memoryview.tolist`, which
    is the nested list representation of the view. If ``view.ndim = 1``,
    this is equal to the number of elements in the view.
@@ -4669,8 +4671,6 @@ copying.
       >>> hash(v[::-2]) == hash(b'abcefg'[::-2])
       True
 
-   memoryviews are :ref:`generic <generics>` over the type of their underlying data.
-
    .. versionchanged:: 3.3
       One-dimensional memoryviews can now be sliced.
       One-dimensional memoryviews with formats 'B', 'b' or 'c' are now :term:`hashable`.