docs: update Kubernetes deployments

docs/how-tos/backup-to-s3.md

@@ -82,53 +82,3 @@ networks:
   web:
 ```
 
-## Deploy on Kubernetes
-
-For Kubernetes, you don't need to run it in scheduled mode. You can deploy it as CronJob.
-
-### Simple Kubernetes CronJob usage:
-
-```yaml
-apiVersion: batch/v1
-kind: CronJob
-metadata:
-  name: bkup-job
-spec:
-  schedule: "0 1 * * *"
-  jobTemplate:
-    spec:
-      template:
-        spec:
-          containers:
-          - name: mysql-bkup
-            image: jkaninda/mysql-bkup
-            command:
-            - /bin/sh
-            - -c
-            - backup -s s3 --path /custom_path
-            env:
-              - name: DB_PORT
-                value: "3306" 
-              - name: DB_HOST
-                value: ""
-              - name: DB_NAME
-                value: ""
-              - name: DB_USERNAME
-                value: ""
-              # Please use secret!
-              - name: DB_PASSWORD
-                value: ""
-              - name: AWS_S3_ENDPOINT
-                value: "https://s3.amazonaws.com"
-              - name: AWS_S3_BUCKET_NAME
-                value: "xxx"
-              - name: AWS_REGION
-                value: "us-west-2"    
-              - name: AWS_ACCESS_KEY
-                value: "xxxx"        
-              - name: AWS_SECRET_KEY
-                value: "xxxx"    
-              - name: AWS_DISABLE_SSL
-                value: "false"
-          restartPolicy: OnFailure
-```