Update the link of kustomization file

The page of kustomize/docs/glossary.md has been moved from
https://github.com/kubernetes-sigs/kustomize to
https://kubernetes-sigs.github.io/kustomize/api-reference/glossary/
This updates the link.

Author: Kenichi Omichi

content/en/docs/tasks/manage-kubernetes-objects/kustomization.md

@@ -8,7 +8,7 @@ weight: 20
 
 [Kustomize](https://github.com/kubernetes-sigs/kustomize) is a standalone tool
 to customize Kubernetes objects
-through a [kustomization file](https://github.com/kubernetes-sigs/kustomize/blob/master/docs/glossary.md#kustomization).
+through a [kustomization file](https://kubernetes-sigs.github.io/kustomize/api-reference/glossary/#kustomization).
 
 Since 1.14, Kubectl also
 supports the management of Kubernetes objects using a kustomization file.