Add example for jsonnet using functions with top level arguments (#30)

jsonnet-guestbook-tla/guestbook-ui.jsonnet

@@ -0,0 +1,65 @@
+function (
+    containerPort=80, 
+    image="gcr.io/heptio-images/ks-guestbook-demo:0.2", 
+    name="jsonnet-guestbook-ui",
+    replicas=1,
+    servicePort=80, 
+    type="LoadBalancer"
+)
+    [
+    {
+        "apiVersion": "v1",
+        "kind": "Service",
+        "metadata": {
+            "name": name
+        },
+        "spec": {
+            "ports": [
+                {
+                "port": servicePort,
+                "targetPort": containerPort
+                }
+            ],
+            "selector": {
+                "app": name
+            },
+            "type": type
+        }
+    },
+    {
+        "apiVersion": "apps/v1beta2",
+        "kind": "Deployment",
+        "metadata": {
+            "name": name
+        },
+        "spec": {
+            "replicas": replicas,
+            "revisionHistoryLimit": 3,
+            "selector": {
+                "matchLabels": {
+                "app": name
+                },
+            },
+            "template": {
+                "metadata": {
+                "labels": {
+                    "app": name
+                }
+                },
+                "spec": {
+                "containers": [
+                    {
+                        "image": image,
+                        "name": name,
+                        "ports": [
+                        {
+                            "containerPort": containerPort
+                        }
+                        ]
+                    }
+                ]
+                }
+            }
+        }
+    }
+    ]