message: [docs] add a link to versioned docs in the docs
diff: @@ -53,6 +53,7 @@ intelligence web application
  Superset Resources
  ==================
  +- Versioned versions of this documentation: https://readthedocs.org/projects/apache-superset/
  - `Superset's Github <https://github.com/apache/incubator-superset>`_, note
  that `we use Github for issue tracking <https://github.com/apache/incubator-superset/issues>`_
  - Superset's
  