let apiserver support api discovery

api/swagger-spec/resourceListing.json

@@ -9,6 +9,10 @@
     "path": "/api",
     "description": "get available API versions"
    },
+   {
+    "path": "/apis",
+    "description": "get available API versions"
+   },
    {
     "path": "/version",
     "description": "git code version from which this is built"

api/swagger-spec/v1.json

@@ -10950,6 +10950,25 @@
       ]
      }
     ]
+   },
+   {
+    "path": "/api/v1",
+    "description": "API at /api/v1 version v1",
+    "operations": [
+     {
+      "type": "void",
+      "method": "GET",
+      "summary": "get available resources",
+      "nickname": "getAPIResources",
+      "parameters": [],
+      "produces": [
+       "application/json"
+      ],
+      "consumes": [
+       "application/json"
+      ]
+     }
+    ]
    }
   ],
   "models": {