Fix markup

pep-0008.txt

@@ -841,16 +841,20 @@ Programming Recommendations
   whenever they do something other than acquire and release resources.
   For example:
 
-      Yes:     with conn.begin_transaction():
+  Yes::
+
+               with conn.begin_transaction():
                    do_stuff_in_transaction(conn)
 
-      No:      with conn:
+  No::
+
+               with conn:
                    do_stuff_in_transaction(conn)
 
-   The latter example doesn't provide any information to indicate that
+  The latter example doesn't provide any information to indicate that
-   the __enter__ and __exit__ methods are doing something other than
+  the __enter__ and __exit__ methods are doing something other than
-   closing the connection after a transaction.  Being explicit is
+  closing the connection after a transaction.  Being explicit is
-   important in this case.
+  important in this case.
 
 - Use string methods instead of the string module.