Issue #26462: Doc: avoid literal_block warnings, fix syntax highlighting.

Patch by Julien Palard.
diff --git a/Doc/tutorial/controlflow.rst b/Doc/tutorial/controlflow.rst
index 2af60d0..e1ac89f 100644
--- a/Doc/tutorial/controlflow.rst
+++ b/Doc/tutorial/controlflow.rst
@@ -473,7 +473,9 @@
               client="John Cleese",
               sketch="Cheese Shop Sketch")
 
-and of course it would print::
+and of course it would print:
+
+.. code-block:: none
 
    -- Do you have any Limburger ?
    -- I'm sorry, we're all out of Limburger
diff --git a/Doc/tutorial/interpreter.rst b/Doc/tutorial/interpreter.rst
index 5f37504..50e50c7 100644
--- a/Doc/tutorial/interpreter.rst
+++ b/Doc/tutorial/interpreter.rst
@@ -93,7 +93,9 @@
 usually three greater-than signs (``>>>``); for continuation lines it prompts
 with the *secondary prompt*, by default three dots (``...``). The interpreter
 prints a welcome message stating its version number and a copyright notice
-before printing the first prompt::
+before printing the first prompt:
+
+.. code-block:: shell-session
 
    python
    Python 2.7 (#1, Feb 28 2010, 00:02:06)
diff --git a/Doc/tutorial/modules.rst b/Doc/tutorial/modules.rst
index 7b6fd9c..0ef07a3 100644
--- a/Doc/tutorial/modules.rst
+++ b/Doc/tutorial/modules.rst
@@ -135,7 +135,9 @@
 
 you can make the file usable as a script as well as an importable module,
 because the code that parses the command line only runs if the module is
-executed as the "main" file::
+executed as the "main" file:
+
+.. code-block:: shell-session
 
    $ python fibo.py 50
    1 1 2 3 5 8 13 21 34