[doc] Fix a few margins due to bad markup (GH-23619)



diff --git a/Doc/library/dialog.rst b/Doc/library/dialog.rst
index dc82a97..53f98c1 100644
--- a/Doc/library/dialog.rst
+++ b/Doc/library/dialog.rst
@@ -198,7 +198,7 @@
    A subclass of FileDialog that creates a dialog window for selecting a
    destination file.
 
-    .. method:: ok_command()
+   .. method:: ok_command()
 
       Test whether or not the selection points to a valid file that is not a
       directory. Confirmation is required if an already existing file is