Comment 3 for bug 1640654

Reviewed: https://review.openstack.org/395925
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=da1148a7a759a6e54be1688b7a2d73e19498099d
Submitter: Jenkins
Branch: master

commit da1148a7a759a6e54be1688b7a2d73e19498099d
Author: Kevin_Zheng <email address hidden>
Date: Thu Nov 10 11:49:20 2016 +0800

    Add flavor extra_spec info link to api_ref

    In the current api-ref, we have illustrated
    about how to add extra specs for flavors,
    but it was very simple and we have a large
    number of built-in extra specs that can be
    used to archive different purpose listed here:
    http://docs.openstack.org/admin-guide/compute-flavors.html

    The reader will still be confused about how
    to correctly use extra specs only read the
    api-ref. We could first simply add the above
    link to the flavor extra spec section in
    api-ref to let readers know where to find
    information and come up with better solution
    later.

    Change-Id: Ie720973783f153d3954be9f4bd97e7f9bf788c6b
    Closes-bug: #1640654