Update Sphinx directive for super from function to class (GH-25489)

diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index 30f62e6..72441f0 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -1677,7 +1677,7 @@
    .. versionchanged:: 3.8
       The *start* parameter can be specified as a keyword argument.
 
-.. function:: super([type[, object-or-type]])
+.. class:: super([type[, object-or-type]])
 
    Return a proxy object that delegates method calls to a parent or sibling
    class of *type*.  This is useful for accessing inherited methods that have