Update hellonode.md to use the kubectl set image command
Update hellonode.md to use the kubectl set image command

Updated to use new command (which should simplify user experience) and update references from 1.2 to 1.3
rata/kubernetes.github.io,ronaldpetty/kubernetes.github.io,rata/kubernetes.github.io,rata/kubernetes.github.io,aidevops/kubernetes.github.io,erictune/erictune.github.io,ronaldpetty/kubernetes.github.io,ronaldpetty/kubernetes.github.io,aidevops/kubernetes.github.io,aidevops/kubernetes.github.io,rata/kubernetes.github.io,aidevops/kubernetes.github.io,erictune/erictune.github.io,erictune/erictune.github.io,erictune/erictune.github.io,erictune/erictune.github.io,aidevops/kubernetes.github.io,rata/kubernetes.github.io