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/service.md

@@ -0,0 +1,19 @@
+---
+title: Service
+id: service
+date: 2018-04-12
+full_link: /docs/concepts/services-networking/service/
+short_description: >
+  An API object that describes how to access applications, such as a set of Pods, and can describe ports and load-balancers.
+
+aka: 
+tags:
+- fundamental
+- core-object
+---
+ An API object that describes how to access applications, such as a set of {{< glossary_tooltip text="Pods" term_id="pod" >}}, and can describe ports and load-balancers.
+
+<!--more--> 
+
+The access point can be internal or external to the cluster.
+