Hmm... I just checked and the code boxes are all populated. Maybe the stylesheet is not working for you. What browser and OS are you using to view the document? Are other code samples readable in the rest of the document?
After running "mvn clean install" at the top-level of the project (e.g., under trunk), you should find the REST service's WAR file in the "dna-web-jcr-rest-war" project (in the extensions folder) at "./extensions/dna-web-jcr-rest-war/target/resources.war".
Yeah, something must have been up with my system. I see the boxes now and the maven instructions.