docs: dashboard guide updates

* kubernetes dashboard guide fixes.

* Update dashboard ingress annotations

docs/content/guides/kubernetes-dashboard.md

@@ -111,7 +111,7 @@ extraVolumes:
               - key: ca.crt
                 path: ca.crt
 extraVolumeMounts:
-  - mountPath: /var/run/secrets/kubernetes.io/serviceaccount/
+  - mountPath: /var/run/secrets/kubernetes.io/serviceaccount
     name: token-ca
 
 ingress:
@@ -119,6 +119,7 @@ ingress:
   annotations:
     nginx.ingress.kubernetes.io/auth-signin: https://${DASHBOARD_URL}/oauth2/start?rd=$escaped_request_uri
     nginx.ingress.kubernetes.io/auth-url: https://${DASHBOARD_URL}/oauth2/auth
+    nginx.ingress.kubernetes.io/auth-response-headers: "authorization"
   hosts:
     - ${DASHBOARD_URL}
   tls: