Linking to API object definitions from docs

docs/user-guide/services.md

@@ -56,6 +56,7 @@ Documentation for other releases can be found at
   - [The gory details of virtual IPs](#the-gory-details-of-virtual-ips)
     - [Avoiding collisions](#avoiding-collisions)
     - [IPs and VIPs](#ips-and-vips)
+  - [API Object](#api-object)
 
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@@ -526,6 +527,12 @@ of which `Pods` they are actually accessing.
 
 ![Services detailed diagram](services-detail.png)
 
+## API Object
+
+Service is a top-level resource in the kubernetes REST API. More details about the
+API object can be found at: [Service API
+object](https://htmlpreview.github.io/?https://github.com/GoogleCloudPlatform/kubernetes/HEAD/docs/api-reference/definitions.html#_v1_service).
+
 
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