Add node-placement info to ‘oc new-app’ description.
Add node-placement info to ‘oc new-app’ description.

- For ‘oc new-app -o’ example, use YAML instead of JSON.
- Add section "Useful Edits" with example "Deploy to Selected Nodes".

xiaoping378/openshift-docs,xiaoping378/openshift-docs,xiaoping378/openshift-docs