The logic in the previous fix for supporting directory comparison was
incorrect. It was using the last commit in the target directory for
history checking. However, some files in the target directory might be
out of sync long before the last commit to the directory.
This PR changes the script to do a history checking on a per-file basis.
This PR improves the lsync script so that it can handle directories
(recursively). For example, you can run the following command to find
the detailed changes that are out of sync:
```
./scripts/lsync content/zh/docs/concepts/_index.md
```
and you can run the following command to identify how many files are
out of sync under a given directory:
```
> ./scripts/lsync content/zh/docs/concepts/
content/en/docs/concepts/architecture/control-plane-node-communication.md | 2 +-
content/en/docs/concepts/architecture/controller.md | 10 ++++++++++
content/en/docs/concepts/cluster-administration/logging.md | 4 ++--
content/en/docs/concepts/cluster-administration/system-metrics.md | 2 +-
content/en/docs/concepts/configuration/pod-priority-preemption.md | 2 +-
content/en/docs/concepts/containers/runtime-class.md | 2 +-
content/en/docs/concepts/extend-kubernetes/compute-storage-net/device-plugins.md | 2 +-
content/en/docs/concepts/extend-kubernetes/operator.md | 2 +-
content/en/docs/concepts/extend-kubernetes/service-catalog.md | 2 +-
content/en/docs/concepts/overview/kubernetes-api.md | 2 +-
content/en/docs/concepts/overview/what-is-kubernetes.md | 3 +--
content/en/docs/concepts/overview/working-with-objects/labels.md | 2 +-
content/en/docs/concepts/scheduling-eviction/kube-scheduler.md | 4 ++--
content/en/docs/concepts/services-networking/dual-stack.md | 2 +-
content/en/docs/concepts/storage/ephemeral-volumes.md | 11 +++++------
content/en/docs/concepts/storage/persistent-volumes.md | 2 +-
content/en/docs/concepts/storage/storage-classes.md | 2 +-
content/en/docs/concepts/storage/volumes.md | 5 ++---
content/en/docs/concepts/workloads/_index.md | 2 +-
content/en/docs/concepts/workloads/controllers/replicaset.md | 4 ++--
content/en/docs/concepts/workloads/pods/_index.md | 4 ++--
content/en/docs/concepts/workloads/pods/pod-lifecycle.md | 3 ++-
```
This PR adds a utility script for localization team to check changes
made to the English (upstream) source since last time the localized
version is updated (synchronized).