Initial "usage" documentation.

README.md

@@ -4,4 +4,26 @@ An operator to install and configure [Shipwright](https://shipwright.io) on Kube
 
 ## Contributing
 
-See [CONTRIBUTING.md](CONTRIBUTING.md) for more information on how to build, test, and submit contributions to the operator.
+See [CONTRIBUTING.md](CONTRIBUTING.md) for more information on how to build, test, and submit
+contributions to the operator.
+
+## Usage
+
+To deploy and manage instances of [Shipwright Build-Controller][build-controller], make sure this
+operator is up-and-running, and then create the following:
+
+```yml
+---
+apiVersion: operator.shipwright.io/v1alpha1
+kind: ShipwrightBuild
+metadata:
+  name: shipwright-operator
+spec:
+  namespace: default
+```
+
+It will deploy the Build-Controller in `default` namespace. When `.spec.namespace` is not informed,
+it will use the `shipwright-build` namespace instead, this namespace needs to be created before the
+actual deployment takes place.
+
+[build-controller]: https://github.com/shipwright-io/build