Don't format the style output as a Python type

Closes #609
diff --git a/CHANGELOG b/CHANGELOG
index e1d4f81..faa32c2 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -22,6 +22,9 @@
 - Cloning a pytree node doesn't transfer its a annotations. Make sure we do
   that so that we don't lose information.
 - Revert change that broke the "no_spaces_around_binary_operators" option.
+- The "--style-help" option would output string lists and sets in Python types.
+  If the output was used as a style, then it wouldn't parse those values
+  correctly.
 
 ## [0.23.0] 2018-08-27
 ### Added