fix: k8s dashboard link.

k8s dashboard required https.
http does not currently have a corresponding endpoint.
So if you try to access it like this, you will get an error: "no endpoints available for service".

Author: kahirokunn

content/en/docs/tasks/access-application-cluster/web-ui-dashboard.md

@@ -55,7 +55,7 @@ You can access Dashboard using the kubectl command-line tool by running the foll
 kubectl proxy
 ```
 
-Kubectl will make Dashboard available at [http://localhost:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:/proxy/](http://localhost:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:/proxy/).
+Kubectl will make Dashboard available at [http://localhost:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:https/proxy/](http://localhost:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:https/proxy/).
 
 The UI can _only_ be accessed from the machine where the command is executed. See `kubectl proxy --help` for more options.