Add the directive to include the configuration options to the library
documentation.
Depends-On: I549c8db98bf548dd0a7e8869a57301fa4096f78c
(feature change in oslo.config)
Depends-On: I89e3e4fd41ed4c989c2dd4c9cd1d7b7e806fa15a
(global requirements change to update oslo.config version)
Change-Id: Ibec7071027fc33374a73abc30f8f672380bae6ea