topic: rename the 'topic-mode' help subtopic
This will help making reference to it in warning.
--- a/hgext3rd/topic/__init__.py Sun Oct 01 00:44:41 2017 +0100
+++ b/hgext3rd/topic/__init__.py Sun Oct 01 09:05:42 2017 +0100
@@ -49,8 +49,8 @@
Be aware that this extension is still an experiment, commands and other features
are likely to be change/adjusted/dropped over time as we refine the concept.
-Config option
-=============
+topic-mode
+==========
The topic extension can be configured to ensure the user do not forget to add
a topic when committing a new topic::