message: Fix a type error in rst' sub list.
  Sub list in rst requires a blank line above and below.
  Ref:
diff: @@ -13,9 +13,11 @@ Feature Overview
  visualization capabilities
  - Browse database metadata: tables, columns, indexes, partitions
  - Support for long-running queries
  +
  - uses the `Celery distributed queue <http://www.python.org/>`_
  to dispatch query handling to workers
  - supports defining a "results backend" to persist query results
  +
  - A search engine to find queries executed in the past
  - Supports templating using the
  `Jinja templating language <http://jinja.pocoo.org/docs/dev/>`_
  