right now, there are duplicate titles under contents --> guides as shown in https://docs.openstack.org/devstack/latest/, although they will forward to different pages, it is still a little confusing for users. This change will hide toctree in guides.rst and users could click links in page to jump to detail page to read more. Change-Id: I2f3abeca7f56a3aedeabb48630ed2c61635b93cd (cherry picked from commit1639594938) (cherry picked from commit90b9964384)