Add Pre/PostSync job example

pre-post-sync/components/pre-sync-job.yaml

@@ -0,0 +1,15 @@
+apiVersion: batch/v1
+kind: Job
+metadata:
+  generateName: before-
+  annotations:
+    argocd.argoproj.io/hook: PreSync
+spec:
+  template:
+    spec:
+      containers:
+      - name: sleep
+        image: alpine:latest
+        command: ["sleep", "30"]
+      restartPolicy: Never
+  backoffLimit: 4