Fix copy-friendliness of tutorial example (GH-93424)

(cherry picked from commit 34d11f1b)

Co-authored-by: Chenwei Xiao <chanvinxiao@163.com>

Doc/tutorial/stdlib2.rst

@@ -108,6 +108,7 @@ placeholders such as the current date, image sequence number, or file format::
    >>> photofiles = ['img_1074.jpg', 'img_1076.jpg', 'img_1077.jpg']
    >>> class BatchRename(Template):
    ...     delimiter = '%'
+   ...
    >>> fmt = input('Enter rename style (%d-date %n-seqnum %f-format):  ')
    Enter rename style (%d-date %n-seqnum %f-format):  Ashley_%n%f