Refine main readme for cert-manager and kubectl version

deployment/kubernetes/README.md

@@ -46,6 +46,10 @@ Please have a look here:
 
 - [Installing with Helm](https://cert-manager.io/docs/installation/helm/#installing-with-helm)
 
+Our Helm installation is optimized for cert-manager version `v1.9.1` and `kubectl` version `"v1.24.2`.
+
+Please search here for cert-manager versions that are compatible with your `kubectl` version on the cluster and on the client: [cert-manager Supported Releases](https://cert-manager.io/docs/installation/supported-releases/#supported-releases).
+
 ***ATTENTION:*** *When uninstalling cert-manager, be sure to use the same method as for installation! Otherwise, we could end up in a broken state, see [Uninstall](https://cert-manager.io/docs/installation/kubectl/#uninstalling).*
 
 <!-- #### 1. Create Namespace
@@ -75,19 +79,19 @@ $ helm repo update
 # kubeconfig.yaml set globaly
 $ helm install cert-manager jetstack/cert-manager \
   --namespace cert-manager \
-  --version v1.1.0 \
+  --version v1.9.1 \
   --set installCRDs=true
 # or kubeconfig.yaml in your repo, then adjust
 $ helm --kubeconfig=/../kubeconfig.yaml \
   install cert-manager jetstack/cert-manager \
   --namespace cert-manager \
-  --version v1.1.0 \
+  --version v1.9.1 \
   --set installCRDs=true
 ``` -->
 
 ### Ingress-Nginx
 
-#### 1. Add Helm repository and update
+#### 1. Add Helm repository for `ingress-nginx` and update
 
 ```bash
 $ helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
@@ -160,7 +164,7 @@ $ doctl compute firewall get <ID> --context <context-name>
 This chart is only necessary (recommended is more precise) if you run DigitalOcean without load balancer.
 You need to generate an access token with read + write for the `dns.values.yaml` at <https://cloud.digitalocean.com/account/api/tokens> and fill it in.
 
-#### 1. Add Helm repository and update
+#### 1. Add Helm repository for `binami` and update
 
 ```bash
 $ helm repo add bitnami https://charts.bitnami.com/bitnami