add "document-start" 1st line to all yaml files

The YAML Specification requires three daashes `---` as marker for the
start of a content block. That means, each YAML file needs to start with
`---` on the first line (or after initial comments).

See-also: https://yaml.org/

.github/workflows/dependabot.yaml

@@ -1,3 +1,4 @@
+---
 version: 2
 updates:
 - package-ecosystem: gomod

.github/workflows/trivy.yaml

@@ -1,3 +1,4 @@
+---
 name: Trivy vulnerability scanner
 on:
   push:

client/config/crd/kustomization.yaml

@@ -1,3 +1,4 @@
+---
 apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
 resources:

deploy/kubernetes/csi-snapshotter/kustomization.yaml

@@ -1,3 +1,4 @@
+---
 apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
 resources:

deploy/kubernetes/csi-snapshotter/rbac-csi-snapshotter.yaml

@@ -8,6 +8,7 @@
 # - optionally rename the non-namespaced ClusterRole if there
 #   are conflicts with other deployments
 
+---
 apiVersion: v1
 kind: ServiceAccount
 metadata:

deploy/kubernetes/csi-snapshotter/rbac-external-provisioner.yaml

@@ -8,6 +8,7 @@
 #   provisioner, in which case leadership election must be enabled;
 #   this influences the RBAC setup, see below
 
+---
 apiVersion: v1
 kind: ServiceAccount
 metadata:

deploy/kubernetes/snapshot-controller/kustomization.yaml

@@ -1,3 +1,4 @@
+---
 apiVersion: kustomize.config.k8s.io/v1beta1
 kind: Kustomization
 resources:

deploy/kubernetes/snapshot-controller/rbac-snapshot-controller.yaml

@@ -5,6 +5,7 @@
 # namespace for components implementing base system functionality. For installing with
 # Vanilla Kubernetes, kube-system makes sense for the namespace.
 
+---
 apiVersion: v1
 kind: ServiceAccount
 metadata:

deploy/kubernetes/webhook-example/rbac-snapshot-webhook.yaml

@@ -5,6 +5,7 @@
 # namespace for components implementing base system functionality. For installing with
 # Vanilla Kubernetes, kube-system makes sense for the namespace.
 
+---
 apiVersion: v1
 kind: ServiceAccount
 metadata:

deploy/kubernetes/webhook-example/webhook.yaml

@@ -1,3 +1,4 @@
+---
 apiVersion: apps/v1
 kind: Deployment
 metadata:

examples/kubernetes/invalid-snapshot-v1.yaml

@@ -1,3 +1,4 @@
+---
 apiVersion: snapshot.storage.k8s.io/v1
 kind: VolumeSnapshot
 metadata:

examples/kubernetes/pvc.yaml

@@ -1,3 +1,4 @@
+---
 apiVersion: v1
 kind: PersistentVolumeClaim
 metadata:

examples/kubernetes/restore.yaml

@@ -1,3 +1,4 @@
+---
 apiVersion: v1
 kind: PersistentVolumeClaim
 metadata:

examples/kubernetes/snapshot-v1.yaml

@@ -1,3 +1,4 @@
+---
 apiVersion: snapshot.storage.k8s.io/v1
 kind: VolumeSnapshot
 metadata:

examples/kubernetes/snapshotclass-v1.yaml

@@ -1,3 +1,4 @@
+---
 apiVersion: snapshot.storage.k8s.io/v1
 kind: VolumeSnapshotClass
 metadata:

examples/kubernetes/storageclass.yaml

@@ -1,3 +1,4 @@
+---
 apiVersion: storage.k8s.io/v1
 kind: StorageClass
 metadata: