step with headings

title: Enable authentication on each component in the cluster.
stepnum: 2
ref: enable-auth
pre:
  Enable authentication by specifying the key file on each
  :program:`mongos` and :program:`mongod` in the cluster, including each
  config server and shard. On each, specify the key file by doing one of
  the following:
action:
  - heading: Specify the key file in the configuration file.
    pre:
      In the configuration file, set the :setting:`keyFile` option to the
      key file's path and then start the component, as in the following
      example:
    language: cfg
    code: |
      keyFile = /srv/mongodb/keyfile
  - heading: Specify the key file at runtime.
    pre:
      When starting the component, set the :option:`--keyFile <mongos --keyFile>`
      option, which is an option for both :program:`mongos`
      instances and :program:`mongod` instances. Set the
      :option:`--keyFile <mongos --keyFile>` to the key file's path. The
      :setting:`keyFile` setting implies :setting:`auth`, which means in
      most cases you do not need to set :setting:`auth` explicitly.
---

lines 8 and 14 in the example above