message: add entity links example json
diff: @@ -54,6 +54,11 @@ software catalog API.
  "labels": {
  "system": "public-websites"
  },
  + "links": [{
  + "url": "https://admin.example-org.com",
  + "title": "Admin Dashboard",
  + "icon": "dashboard"
  + }],
  "tags": ["java"],
  "name": "artist-web",
  "uid": "2152f463-549d-4d8d-a94d-ce2b7676c6e2"
  