Update weave-kube docs to mention YAML customisation via the Launch G…

…enerator.

site/kube-addon.md

@@ -26,12 +26,31 @@ After a few seconds, a Weave Net pod should be running on each
 Node and any further pods you create will be automatically attached to the Weave
 network.
 
-N.B.: In Kubernetes versions `1.6` and above, depending on how your cluster is configured, you may need to:
+N.B.:
+- In Kubernetes versions `1.6` and above, depending on how your cluster is configured, you may need to:
 
-- add `sudo`,
-- add `--kubeconfig /etc/kubernetes/admin.conf` or equivalent,
+  - add `sudo`,
+  - add `--kubeconfig /etc/kubernetes/admin.conf` or equivalent,
+
+  to the above `kubectl version` command.
+
+- You can also customise your Kubernetes setup by passing options and arguments as query parameters. For example,
+```
+$ kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')&env.MTU=1337"
+```
+generates a Kubernetes YAML containing:
+
+```
+[...]
+          containers:
+            - name: weave
+[...]
+              env:
+                - name: MTU
+                  value: '1337'
+[...]
+```
 
-to the above `kubectl version` command.
 
 **Note:** This command requires Kubernetes 1.4 or later.