Improve install instructions

Author: Felix Hennig

docs/modules/zookeeper/pages/getting_started/installation.adoc

@@ -1,16 +1,13 @@
 = Installation
+:description: Install the Stackable operator for Apache ZooKeeper using stackablectl or Helm.
 
-On this page you will install the Stackable ZooKeeper Operator.
-
-== Stackable Operators
-
-There are 2 ways to run Stackable Operators
-
-. Using xref:management:stackablectl:index.adoc[] (recommended)
-. Using Helm
-
-=== stackablectl
+Follow the instructions below to install the Stackable operator for Apache ZooKeeper, using either `stackablectl` or Helm:
 
+[tabs]
+====
+stackablectl (recommended)::
++
+--
 `stackablectl` is the command line tool to interact with Stackable operators and our recommended way to install
 Operators. Follow the xref:management:stackablectl:installation.adoc[installation steps] for your platform.
 
@@ -28,10 +25,13 @@ include::example$getting_started/code/install_output.txt[]
 
 TIP: Consult the xref:management:stackablectl:quickstart.adoc[] to learn more about how to use `stackablectl`. For
 example, you can use the `--cluster kind` flag to create a Kubernetes cluster with link:https://kind.sigs.k8s.io/[kind].
+--
 
-=== Helm
-
-You can also use Helm to install the Operators. Add the Stackable Helm repository:
+Helm::
++
+--
+You can also use Helm to install the Operators.
+Add the Stackable Helm repository:
 [source,bash]
 ----
 include::example$getting_started/code/getting_started.sh[tag=helm-add-repo]
@@ -43,9 +43,10 @@ Then install the Stackable Operators:
 include::example$getting_started/code/getting_started.sh[tag=helm-install-operators]
 ----
 
-Helm will deploy the Operators in a Kubernetes Deployment and apply the CRDs for the ZooKeeper cluster. You are now
-ready to deploy Apache ZooKeeper in Kubernetes.
+Helm deploys the operators in Kubernetes Deployments and applies the CRDs for the ZooKeeperCluster Stacklet.
+--
+====
 
-== What's next
+== What's next?
 
-xref:getting_started/first_steps.adoc[Set up a ZooKeeper cluster].
+Use the operator to xref:getting_started/first_steps.adoc[deploy a ZooKeeper Stacklet].