Add docs for building and using custom awx image

docs/build_awx_image.md

@@ -0,0 +1,28 @@
+# Building the AWX Image
+
+## Build & Push Image
+
+To build a custom awx image to use with the awx-operator, use the `build_image` role:
+
+```
+$ ansible-playbook tools/ansible/build.yml -v -e awx_image=registry.example.com/awx -e awx_version=test
+```
+
+This will build an AWX image and tag it.  You can then push that image to your container registry:
+
+
+```
+$ docker push registry.example.com/awx:test
+```
+
+
+## Using this image with the awx-operator
+
+In the spec section of the `my-awx.yml` file described in the [install docs](./../INSTALL.md#deploy-awx),
+specify the new custom image.  
+
+```
+spec:
+  tower_image: registry.example.com/awx
+  tower_image_version: test
+```