Update tkgs.rst with specified k8s versions

docs/install/tkgs.rst

@@ -34,7 +34,7 @@ Minimally required resources for TKG cluster to install Kubeflow
 
 To install Kubeflow, the TKG cluster must meet the following minimum requirements:
 
-- Kubernetes version 1.21 or later
+- Kubernetes version 1.21, 1.22, 1.23, 1.24 or 1.25
 - At least one worker node satisfies below minimum resources requirements:
     - 4 CPU
     - 16GB memory
@@ -331,4 +331,4 @@ Cert-manager is used by Kubeflow components to provide certificates for admissio
 
 This error message indicates that the webhook is not yet ready to receive request. You simply need to wait a couple seconds and retry.
 
-For more troubleshooting info about cert-manager, check https://cert-manager.io/docs/troubleshooting/webhook/
+For more troubleshooting info about cert-manager, check https://cert-manager.io/docs/troubleshooting/webhook/