[INFINITY-2660] Add region/zone documentation (#1841)
[INFINITY-2660] Add region/zone documentation (#1841)

* Add region/zone documentation

* Update developer-guide.md

* Update developer-guide.md

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