zh_Trans: Fix preview issue (#11311)

* zh_trans: kubeadm-upgrade-1-12.md

* update file

* Update _index.md

* Delete _index.md

* Update kubeadm-upgrade-1-12.md

* zh_trans: docs/reference/setup-tools/kubeadm/generated/kubeadm_config.md

* Update kubeadm_config.md

* zh_trans: fix Preview

* zh_trans: fix Preview

content/zh/docs/reference/glossary/secret.md

@@ -0,0 +1,19 @@
+---
+title: Secret
+id: secret
+date: 2018-04-12
+full_link: /docs/concepts/configuration/secret/
+short_description: >
+  Stores sensitive information, such as passwords, OAuth tokens, and ssh keys.
+
+aka: 
+tags:
+- core-object
+- security
+---
+ Stores sensitive information, such as passwords, OAuth tokens, and ssh keys.
+
+<!--more--> 
+
+Allows for more control over how sensitive information is used and reduces the risk of accidental exposure, including [encryption](https://kubernetes.io/docs/tasks/administer-cluster/encrypt-data/#ensure-all-secrets-are-encrypted) at rest.  A {{< glossary_tooltip text="Pod" term_id="pod" >}} references the secret as a file in a volume mount or by the kubelet pulling images for a pod. Secrets are great for confidential data and [ConfigMaps](https://kubernetes.io/docs/tasks/configure-pod-container/configure-pod-configmap/) for non-confidential data.
+