Update the API content in the document to Rocky
Update the API content in the document to Rocky

The current API document for the Cyborg project is still in the
Pike version and is outdated.
Need to update it to the latest Rocky version.

Change-Id: I663e6ed8ff1f99b423528d26533626466a54c530
Story: 2004705
Task: 28734

openstack/nomad