fix: update Helm repository URL to konstruct.io

Author: muse-sisay

docs/common/partials/common/_ui-helm.mdx

@@ -1,7 +1,7 @@
 This will install our platform installer tools to your existing cluster so you can create your new management cluster in your favorite cloud provider using your favorite git provider.
 
 ```shell
-helm repo add kubefirst https://charts.kubefirst.com
+helm repo add kubefirst https://charts.konstruct.io
 helm repo update
 
 helm install kubefirst --namespace kubefirst --create-namespace  kubefirst/kubefirst