Add TLS section to GLBC docs, and BETA_LIMITATIONS

controllers/gce/https_example/tls-app.yaml

@@ -0,0 +1,46 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: echoheaders-https
+  labels:
+    app: echoheaders-https
+spec:
+  type: NodePort
+  ports:
+  - port: 80
+    targetPort: 8080
+    protocol: TCP
+    name: http
+  selector:
+    app: echoheaders-https
+---
+apiVersion: v1
+kind: ReplicationController
+metadata:
+  name: echoheaders-https
+spec:
+  replicas: 2
+  template:
+    metadata:
+      labels:
+        app: echoheaders-https
+    spec:
+      containers:
+      - name: echoheaders-https
+        image: gcr.io/google_containers/echoserver:1.3
+        ports:
+        - containerPort: 8080
+---
+apiVersion: extensions/v1beta1
+kind: Ingress
+metadata:
+  name: test
+spec:
+  tls:
+  # This assumes tls-secret exists.
+  # To generate it run the make in this directory.
+  - secretName: tls-secret
+  backend:
+    serviceName: echoheaders-https
+    servicePort: 80
+