fix(air-gapped): authenticated registry secrets creation

Add examples for the authenticated registry secrets creation

Author: sydorovdmytro

platform/install/advanced/air-gapped.mdx

@@ -161,24 +161,24 @@ Follow these steps to populate the registry with the specific images needed for
   Download the text files from the [vCluster GitHub release](https://github.com/loft-sh/vcluster/releases).
 
   The `images.txt` or `vcluster-images.txt` files contain multiple Kubernetes versions and distributions. You can edit the file and remove the images for any unwanted versions and distributions.
-    
+
   ```bash title="Download image text file for vCluster v0.25.0+ versions"
   wget https://github.com/loft-sh/vcluster/releases/download/v${VCLUSTER_VERSION}/images.txt
   ```
 
   ```bash title="Download image text file for vCluster < v0.25.0 versions"
   wget https://github.com/loft-sh/vcluster/releases/download/v${VCLUSTER_VERSION}/vClusterimages.txt
   ```
-  
+
   </Step>
   <Step>
 
-  **Optional**: Download the scripts from the [vCluster GitHub release](https://github.com/loft-sh/vcluster/releases) and make them executable. 
-  
+  **Optional**: Download the scripts from the [vCluster GitHub release](https://github.com/loft-sh/vcluster/releases) and make them executable.
+
   :::note
   If you've already completed this as part of populating the platform images, you can skip this step.
-  ::: 
-  
+  :::
+
   ```bash title="Download prepare scripts"
    wget https://github.com/loft-sh/vcluster/releases/download/v${VCLUSTER_VERSION}/download-images.sh
    wget https://github.com/loft-sh/vcluster/releases/download/v${VCLUSTER_VERSION}/push-images.sh
@@ -206,7 +206,7 @@ Follow these steps to populate the registry with the specific images needed for
 
   Run `push-images.sh` to upload all required images to your private registry.
 
-  Images are pushed to your private registry without public registry references, preserving only the repository and image name. 
+  Images are pushed to your private registry without public registry references, preserving only the repository and image name.
   You can configure vCluster to use your private registry for all deployments.
 
   ```bash title="Push images to private registry"
@@ -465,16 +465,12 @@ It is recommended to install vCluster Platform on its own host cluster.
   Read more about how to quickly create a [secret from your docker login](https://kubernetes.io/docs/reference/kubectl/generated/kubectl_create/kubectl_create_secret_docker-registry/).
 
   ```bash title="Example of how to create a Kubernetes secret for login credentials"
-  kubectl create -f - <<EOF
-  apiVersion: v1
-  kind: Secret
-  metadata:
-    name: registry-credentials-secret-name
-    namespace: ${PLATFORM_NAMESPACE}
-  type: Opaque
-  data:
-    # Credentials based on your private registry
-  EOF
+  kubectl create secret docker-registry registry-credentials-secret-name \
+    --namespace ${PLATFORM_NAMESPACE} \
+    --docker-server=<your-registry-server> \
+    --docker-username=<your-username> \
+    --docker-password=<your-password> \
+    --docker-email=<your-email>
   ```
 
   </Step>
@@ -530,16 +526,12 @@ chart is adding additional variables to figure out how to connect to the platfor
   For more details, see [Create a Secret from your Docker login](https://kubernetes.io/docs/reference/kubectl/generated/kubectl_create/kubectl_create_secret_docker-registry/).
 
   ```bash title=" Create a Kubernetes secret for login credentials example"
-  kubectl create -f - <<EOF
-  apiVersion: v1
-  kind: Secret
-  metadata:
-    name: registry-credentials-secret-name
-    namespace: ${AGENT_NAMESPACE}
-  type: Opaque
-  data:
-    # Credentials based on your private registry
-  EOF
+  kubectl create secret docker-registry registry-credentials-secret-name \
+    --namespace ${AGENT_NAMESPACE} \
+    --docker-server=<your-registry-server> \
+    --docker-username=<your-username> \
+    --docker-password=<your-password> \
+    --docker-email=<your-email>
   ```
 
   </Step>
@@ -651,7 +643,7 @@ sync:
 
 </details>
 
-### Deploy vCluster through the platform 
+### Deploy vCluster through the platform
 
 When deploying vCluster through the platform console, you'll must add your `vcluster.yaml`.
 
@@ -719,16 +711,12 @@ In the options for the config, there is a section called `Host namespace`, add t
   export VCLUSTER_NAMESPACE=vcluster-my-vcluster  # Replace with the name of the namespace you want to deploy your vCluster into
   kubectl create namespace ${VCLUSTER_NAMESPACE}
 
-  kubectl create -f - <<EOF
-  apiVersion: v1
-  kind: Secret
-  metadata:
-    name: registry-credentials-secret-name
-    namespace: ${VCLUSTER_NAMESPACE}
-  type: Opaque
-  data:
-    # Credentials based on your private registry
-  EOF
+  kubectl create secret docker-registry registry-credentials-secret-name \
+  --namespace ${VCLUSTER_NAMESPACE} \
+  --docker-server=<your-registry-server> \
+  --docker-username=<your-username> \
+  --docker-password=<your-password> \
+  --docker-email=<your-email>
   ```
 
   </Step>