Update customizing-gke.md (kubeflow#999)

Jiaxiao Zheng · k8s-ci-robot · commit 67f6edb1ebdb · 2019-07-30T16:31:09.000-07:00
Correct a typo
diff --git a/content/docs/gke/customizing-gke.md b/content/docs/gke/customizing-gke.md
@@ -52,7 +52,7 @@ To customize the Kubeflow resources running within the cluster you can modify th
 For example, to modify settings for the Jupyter web app:
 
 ```
-cd ${KF_APP}/kustomize
+cd ${KFAPP}/kustomize
 gvim jupyter-web-app.yaml
 ```
 
