resynch with API doc after API migration

[rose-coste]

links to and discussion of API doc here probably won't match the API doc itself post-migration.

• find the places to change
• prep the changes
• publish the changes right after the API doc changes are published

[rose-coste]

https://github.com/rackerlabs/docs-core-infra-user-guide/pull/394 partially addresses this, by updating links to API devguides to use developer.rackspace.com instead of docs.rackspace.com.

links to other API doc (Getting Started with the API, API Release Notes) still point to their docs.rackspace.com locations