docs: how to update CNP docs directions

Former-commit-id: 65f9e99

Author: George Song

docs/how-tos/sync-cnp-docs.md

@@ -0,0 +1,20 @@
+# Sync Cloud-Native-PostgreSQL Docs
+
+Currently we need to manually sync over [cloud-native-postgresql][cnp]("CNP")
+docs whenever there's a new release. The long term goal is to automate this via
+GitHub action dispatch and automated event handling.
+
+1. The CNP team informs us that there's a new version.
+1. Check out the appropriate version from the [CNP][] repo.
+1. Replace `docs:temp_kubernetes/original/` with
+   `cloud-native-postgresql:docs/`.
+1. Transpile original source documentation into MDX format:
+
+   ```sh
+   python scripts/source/source_cloud_native_operator.py
+   ```
+
+1. Replace `advocacy_docs/kubernetes/cloud-native-postgresql/` with
+   `temp_kubernetes/build/`.
+
+[cnp]: https://github.com/EnterpriseDB/cloud-native-postgresql