Security Guide - Add typographic convention for reader substitutions in examples

[Lucas Fisher]

Many examples have values for which readers should substitute their own values. For example:
   service_password = password
Where the reader should substitute their own value for password. Add a typographic convention to make it obvious that the reader should be replacing this value. Something like make it bold, use brackets (<your password>), etc.

[Andreas Jaeger (jaegerandi)]

Let's follow the conventions we use for the Install Guide - see https://wiki.openstack.org/wiki/Documentation/Conventions#Install_Guide.

This would be <replaceable>SERVICE_PASSWORD</replaceable>

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/110173

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/110173
Committed: https://git.openstack.org/cgit/openstack/security-doc/commit/?id=8e0237a3f63d50aaa70d3100a81f935c6b20b02a
Submitter: Jenkins
Branch: master

commit 8e0237a3f63d50aaa70d3100a81f935c6b20b02a
Author: KATO Tomoyuki <email address hidden>
Date: Tue Jul 29 23:11:40 2014 +0900

    Add typographic convention for reader substitutions in examples

    follow the conventions of Install Guide
    https://wiki.openstack.org/wiki/Documentation/Guide_conventions

    Change-Id: Ie8970168dbdc850fac7f0d196c936bad8d872e62
    Closes-Bug: 1342370