🐞 bug: PITR's README.md should add the description that PITR backup record files are stored in the hidden folder，and how to restore when change host.

[peilinqian]

Environment

• Contents of your values.yaml file,if your helm deployment process goes wrong.
• Contents of your CRD resource file. Include proxy.shardingsphere.apache.org/v1alpha1 and proxyconfig.shardingsphere.apache.org/v1alpha1
• Kubernetes distro (e.g. RKE/K3s/EKS/OpenShift) and version

Issue description

• Which phase is not functioning properly, is it the installation phase or the apply CRD phase ?
  PITR's README.md should add the description that PITR backup record files are stored in the hidden folder，and how to restore when change host

Error log

• Including ShardingSphere-Proxy error log and ShardingSphere-Operator error log

Expected result

No response

[mlycore]

This is updated in PR #475. Refers: https://stackgres.io/doc/latest/reference/crd/sgshardedcluster/