docs: fix reST syntax and whitespace in executemany examples

doc/src/cursor.rst

@@ -208,6 +208,8 @@ The ``cursor`` class
         Parameters are bounded to the query using the same rules described in
         the `~cursor.execute()` method.
 
+        .. code:: python
+
             >>> nums = ((1,), (5,), (10,))
             >>> cur.executemany("INSERT INTO test (num) VALUES (%s)", nums)
 

doc/src/extras.rst

@@ -1029,6 +1029,8 @@ parameters.  By reducing the number of server roundtrips the performance can be
 
 .. autofunction:: execute_batch
 
+    .. code:: python
+
         >>> nums = ((1,), (5,), (10,))
         >>> execute_batch(cur, "INSERT INTO test (num) VALUES (%s)", nums)