documenting the activity configuration options

source/bundles/activity.rst

@@ -23,6 +23,29 @@ Entities provided
 
    Describe the entities provided.
 
+
+Configuration options
+*********************
+
+Those options are available under `chill_activity` key.
+
+Example of configuration:
+
+.. code-block:: yaml
+
+   chill_activity:
+      form:
+         time_duration: 
+            - { label: '12 minutes', seconds: 720 }
+            - { label: '30 minutes', seconds: 1800 }
+
+form.time_duration *array*
+   The duration which might be suggested when the user create or update an activity. The value must be an array of object, where each object must have a :code:`label` and a :code:`seconds` key. The label provide which is shown to user (the label will be translated, if possible) and the seconds the duration.
+
+   Example: see the example above
+
+   Default value: the values available are 5, 10, 15, 20, 25, 30, 45 minutes, and 1 hour, 1 hour 15, 1 hour 30, 1 hour 45 and 2 hours.
+
 Macros
 ******