GitHub action to create the kubectl plugins as a release artifact

[devdattakulkarni]

The steps to create the kubectl plugins tar gz are as follows:

KUBEPLUS_HOME=<directory where kubeplus repository is cloned>

cd $KUBEPLUS_HOME
tar -cvf kubeplus-kubectl-plugins.tar plugins/
gzip kubeplus-kubectl-plugins.tar

These steps will be included in the GitHub action. The GH action should be defined to be triggered manually.

[devdattakulkarni]

@chiukapoor Are the above steps enough for creating the GH to create the plugins artifact?