add gcs

Author: ifanfairuz

.env.example

@@ -7,3 +7,9 @@ JWT_EXPIRES_IN=7d
 GOOGLE_CLIENT_ID=your-google-client-id
 GOOGLE_CLIENT_SECRET=your-google-client-secret
 GOOGLE_CALLBACK_URL=http://localhost:3000/auth/google/callback
+
+GCS_CREDENTIALS={"type":"service_account","project_id":"...","private_key":"...","client_email":"..."}
+# GCS_KEYFILE_PATH=path/to/service-account-key.json
+GCS_PROJECT_ID=your-gcp-project-id
+GCS_BUCKET_NAME=your-gcs-bucket-name
+GCS_BASE_PATH=lifelines