Add Secrets and DCOS_SPACE in Operation Guide (#1194)
Add Secrets and DCOS_SPACE in Operation Guide (#1194)

* Add Secrets and DCOS_SPACE in Operation Guide

* Add starting example for Secrets in doc

* Specify Enterprise DC/OS for Secrets support in docs

mesosphere/dcos-commons,vishnu2kmohan/dcos-commons,mesosphere/dcos-commons,vishnu2kmohan/dcos-commons,mesosphere/dcos-commons,mesosphere/dcos-commons,vishnu2kmohan/dcos-commons,mesosphere/dcos-commons,vishnu2kmohan/dcos-commons,vishnu2kmohan/dcos-commons