Separate source link from main text.
diff --git a/Doc/library/string.rst b/Doc/library/string.rst
index 904df29..32fda13 100644
--- a/Doc/library/string.rst
+++ b/Doc/library/string.rst
@@ -13,6 +13,8 @@
 
 **Source code:** :source:`Lib/string.py`
 
+--------------
+
 String constants
 ----------------