Ko: 1st Korean l10n work for release-1.20

- Translate reference/glossary/persistent-volume.md in Korean (#25474)
- Update outdated files in the dev-1.20-ko.1 branch (1) (#25576)
- Translate blog/dont-panic-kubernetes-and-docker into Korean (#25596)
- Update outdated files in the dev-1.20-ko.1 branch(3) (#25728)
- Ko: enhance tutorials//cluster-intro translation (#25754)
- Fix Outdated files in the dev-1.20-ko.1 branch (2) (#25765)

Co-authored-by: seokho-son <shsongist@gmail.com>
Co-authored-by: jmyung <jesang.myung@gmail.com>
Co-authored-by: Jerry Park <jaehwa@gmail.com>
Co-authored-by: santachopa <santachopa@naver.com>
Co-authored-by: SEUNGHYUN KO <kosehy@gmail.com>
Co-authored-by: June Yi <gochist@gmail.com>

content/ko/docs/concepts/storage/volume-snapshot-classes.md

@@ -33,7 +33,7 @@ weight: 30
 생성된 이후에는 업데이트할 수 없다.
 
 ```yaml
-apiVersion: snapshot.storage.k8s.io/v1beta1
+apiVersion: snapshot.storage.k8s.io/v1
 kind: VolumeSnapshotClass
 metadata:
   name: csi-hostpath-snapclass
@@ -47,7 +47,7 @@ parameters:
 기본 볼륨스냅샷클래스를 지정할 수 있다.
 
 ```yaml
-apiVersion: snapshot.storage.k8s.io/v1beta1
+apiVersion: snapshot.storage.k8s.io/v1
 kind: VolumeSnapshotClass
 metadata:
   name: csi-hostpath-snapclass