just use link in tracker.rst

docs/api/tracker.rst

@@ -10,17 +10,8 @@ Tracker
 .. edit-link::
 
 Trackers maintain the state of a dialogue between the assistant and the user in the form
-of conversation sessions. The default conversation session configuration looks as
-follows:
-
-.. code-block:: yaml
-
-  session_config:
-    session_expiration_time: 60  # value in minutes, 0 means infinitely long
-    carry_over_slots_to_new_session: true  # set to false to forget slots between sessions
-
-To learn more about how to configure the session behaviour, check out the docs on
-:ref:`session_config`.
+of conversation sessions. To learn more about how to configure the session behaviour,
+ check out the docs on :ref:`session_config`.
 
 .. edit-link::
    :url: https://github.com/RasaHQ/rasa/edit/master/rasa/core/trackers.py