Add fixes to README

Try investigating and adding

To see live tpcds benchmark results
$./sparkctl forward tpcds
$http://localhost:4040/jobs/

To see dashboard
$ kubectl proxy
$http://localhost:8001/api/v1/namespaces/kube-system/services/https:kubernetes-dashboard:/proxy/#!/overview?namespace=default

To see history-server
$opsparkctl status
$http://137.138.33.78:31402/?showIncomplete=false

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