Add a README to the examples/ folder.

examples/README.md

+# Example Ingress
+
+The YAML configurations in this folder create sample Services and an
+Ingress to test and demonstrate the Ingress implementation -- the
+"cafe" example, inspired by existing Ingress projects.
+
+```
+# Create the Services "coffee-svc" and "tea-svc"
+$ kubectl create -f cafe.yaml
+
+# Create an Ingress that routes requests to the two Services
+$ kubectl create -f cafe-ingress.yaml
+```
+To note:
+
+* The Ingress has the annotation ``kubernetes.io/ingress.class:
+  "varnish"``, identifying it as an Ingress to be implemented by the
+  Varnish controller (the Varnish controller ignores any Ingress that
+  does not have this annotation).
+* Both the Ingress and the Services are created in the
+  ``varnish-ingress`` namespace, as are the resources defined by the
+  configurations in the [``deploy/``](/deploy) folder. The controller
+  currently ignores all definitions that are not defined in the same
+  namespace as the Pod in which it is running (this is likely to
+  become more flexible in future development).
+
+The Ingress rules in the example require that:
+
+* Every request has ``cafe.example.com`` as the value of its ``Host``
+  header.
+  * Otherwise, Varnish answers with a synthetic 404 Not Found
+    response.
+* If the URL path begins with ``/tea``, then the request is routed
+  to the Service ``tea-svc``.
+* If the path begins with ``/coffee``, then the request is routed
+  to the Service ``coffee-svc``.
+* For any other URL path, Varnish responds with 404 Not Found.
+
+In the following, assume that ``$ADDR`` is the external address at
+which the Kubernetes cluster receives requests, and that ``$PORT`` is
+the external port for which requests are received by Varnish. (For example,
+the port may have resulted from the NodePort definition in
+[``deploy/nodeport.yaml``](/deploy/nodeport.yaml).)
+
+Then for this curl command:
+```
+$ curl -H 'Host: cafe.example.com' 'http://$ADDR:$PORT/coffee/foo/bar
+```
+... you may receive a response body like this:
+```
+Server address: 172.17.0.17:80
+Server name: coffee-6c47b9cb9c-ldljf
+Date: 21/Nov/2018:15:58:47 +0000
+URI: /coffee
+Request ID: f78d60f0d578792fa76a114d9cb73798
+```
+The "Server address" and "Server name" values indicate that the
+response was generated by the coffee Service.
+
+For this command:
+```
+$ curl -H 'Host: cafe.example.com' 'http://$ADDR:$PORT/tea/baz/quux
+```
+... you may receive a response body like this:
+```
+Server address: 172.17.0.12:80
+Server name: tea-58d4697745-wq278
+Date: 21/Nov/2018:16:05:32 +0000
+URI: /tea/baz/quux
+Request ID: 5cffc81f3be0d98d005257f39c874693
+```
+This response was generated by the tea Service.
+
+These commands lead to a 404 Not Found response for the reasons given:
+```
+# Does not include the required Host header
+$ curl 'http://$ADDR:$PORT/coffee/foo/bar
+
+# URL path does not begin with either of /coffee or /tea
+$ curl -H 'Host: cafe.example.com' 'http://$ADDR:$PORT/milk
+```