Adapt the naming of the folders under yardstick/docs to the naming adopted by
the release documentation defined by opnfvdocs.
JIRA: -
Change-Id: Icc57720d585abbbf7252bcbf76e2f2a403cb1732 Signed-off-by: Ana C <ana.cunha@ericsson.com>
(cherry picked from commit 463a69e878d891b897fe70af15434615baf6a2e9)