Improve highlighting of some code blocks. (GH-6401)

(cherry picked from commit 46936d5a71d1683dbd8ddb6d7f39aab50ecfec50)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
diff --git a/Doc/library/faulthandler.rst b/Doc/library/faulthandler.rst
index d0c4cd0..94ebd87 100644
--- a/Doc/library/faulthandler.rst
+++ b/Doc/library/faulthandler.rst
@@ -152,10 +152,10 @@
 Example
 -------
 
-.. highlight:: sh
-
 Example of a segmentation fault on Linux with and without enabling the fault
-handler::
+handler:
+
+.. code-block:: shell-session
 
     $ python3 -c "import ctypes; ctypes.string_at(0)"
     Segmentation fault