Update examples for new Spark Operator, remove license and add examples in header, update README

docs/spark-k8s-cluster.md

-# Manual creation of spark on kubernetes
-
-### Prerequisites
-
-- kubectl > v1.10.1
-- kubernetes > v1.10 (with Initializers enabled) 
-
-For more details look [here](https://github.com/cerndb/spark-on-k8s-operator/blob/master/opsparkctl/openstack_client.py)
-
-### Manual installation
-
-Get spark-on-k8s-operator
-
-```bash
-git clone https://github.com/cerndb/spark-on-k8s-operator
-```
-
-Install **spark operator prerequisites** on the cluster
-
-```bash
-kubectl apply -f spark-on-k8s-operator/manifest/spark-operator-base
-```
-
-Edit and install **spark operator config** on the cluster
-
-```bash
-vi spark-on-k8s-operator/manifest/spark-operator/spark-config.yaml
-kubectl apply -f spark-on-k8s-operator/manifest/spark-operator/spark-config.yaml
-```
-
-Install **spark operator** on the cluster
-
-```bash
-kubectl apply -f spark-on-k8s-operator/manifest/spark-operator/spark-operator.yaml
-```
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