Remove trailing whitespace.
diff --git a/Doc/library/idle.rst b/Doc/library/idle.rst
index 65101fc..413750f 100644
--- a/Doc/library/idle.rst
+++ b/Doc/library/idle.rst
@@ -230,7 +230,7 @@
    Keywords
       orange
 
-   Strings 
+   Strings
       green
 
    Comments