Update README.md

Added new blog for OCI PostgreSQL Terraform

Author: sylwesterdec

data-platform/open-source-data-platforms/postgresql/README.md

@@ -12,6 +12,7 @@ OCI Database with PostgreSQL is designed for high availability by offering durab
 
 - [OCI PostgreSQL launch blog](https://blogs.oracle.com/cloud-infrastructure/post/oci-database-postgres)
 - [OCI PostgreSQL features](https://blogs.oracle.com/cloud-infrastructure/post/first-principles-optimizing-postgresql-for-the-cloud)
+- [Terraform to deploy OCI PostgreSQL database](https://blogs.oracle.com/cloud-infrastructure/post/deploy-managed-oci-database-with-postgresql-service-with-terraform)
 
 
 # License