[doc] Link to section File input (GH-28941) (GH-29375)

(cherry picked from commit 48824fa1e26595ac97ffc96ee2c3d32ff130c420)

Co-authored-by: Andre Delfino <adelfino@gmail.com>
diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst
index 6894554..47ebbd0 100644
--- a/Doc/library/functions.rst
+++ b/Doc/library/functions.rst
@@ -557,7 +557,7 @@
    a suite of Python statements which is then executed (unless a syntax error
    occurs). [#]_ If it is a code object, it is simply executed.  In all cases,
    the code that's executed is expected to be valid as file input (see the
-   section "File input" in the Reference Manual). Be aware that the
+   section :ref:`file-input` in the Reference Manual). Be aware that the
    :keyword:`nonlocal`, :keyword:`yield`,  and :keyword:`return`
    statements may not be used outside of
    function definitions even within the context of code passed to the