added preinstall script details

Author: ozRunAI

docs/admin/runai-setup/cluster-setup/cluster-prerequisites.md

@@ -381,10 +381,39 @@ Once you believe that the Run:ai prerequisites are met, we highly recommend inst
 
 To use the script [download](https://github.com/run-ai/preinstall-diagnostics/releases){target=_blank} the latest version of the script and run:
 
-```
-chmod +x preinstall-diagnostics-<platform>
-./preinstall-diagnostics-<platform>
-```
+
+
+=== "SaaS"
+* On EKS deployments, please run aws configure prior to execution
+
+    ``` bash
+    chmod +x ./preinstall-diagnostics-darwin-arm64 && \
+  ./preinstall-diagnostics-darwin-arm64 \
+      --domain ${TENANT_NAME}.run.ai \
+      --cluster-domain ${CLUSTER_FQDN}
+    ```
+
+=== "Self-hosted"
+
+
+    ``` bash
+        chmod +x ./preinstall-diagnostics-darwin-arm64 && ./preinstall-diagnostics-darwin-arm64 \
+      --domain ${CONTROL_PLANE_FQDN} \
+      --cluster-domain ${CLUSTER_FQDN} \
+    #if the diagnostics image is hosted in a private registry
+      --image-pull-secret ${IMAGE_PULL_SECRET_NAME} \
+      --image ${PRIVATE_REGISTRY_IMAGE_URL}    
+    ```
+
+=== "Airgap"
+
+    On an air-gapped deployment, the diagnostics image should be pulled, saved and manually pushed to the organization's registry.
+
+    The binary should be run with --image parameter to modify the diagnostics image to be used:
+
+
+
+
 
 If the script shows warnings or errors, locate the file `runai-preinstall-diagnostics.txt` in the current directory and send it to Run:ai technical support.