gep-713: fixed 'forwardTo' to 'backendRefs' and also 'serviceName'

Author: sanjaypujare

geps/gep-713.md

@@ -1427,8 +1427,8 @@ spec:
     - path:
         type: Prefix
         value: /bar
-    forwardTo:
-    - serviceName: my-service1
+    backendRefs:
+    - name: my-service1
       port: 8080
 ---
 apiVersion: networking.acme.io/v1alpha2