Consolidate YAML files [part-15] (#9380)

This is the last PR for moving the YAML/JSON sample files. There still
need some follow up PRs to:
- rename the `codenew` shortcode to `code`.
- move the examples_test.go to where it really belongs.

content/en/examples/federation/policy-engine-service.yaml

@@ -0,0 +1,13 @@
+kind: Service
+apiVersion: v1
+metadata:
+  name: opa
+  namespace: federation-system
+spec:
+  selector:
+    app: opa
+  ports:
+  - name: http
+    protocol: TCP
+    port: 8181
+    targetPort: 8181