Enhance the README for Shipyard

Provide a start to better documentation for Shipyard by
adding short description to the README file
I anticipate adding links to setup, deploy, and other guides
related to maintenance and use of Shipyard

Change-Id: I2066df674317d48061816418836e676d02a784ed

README.md

@@ -1,2 +1,70 @@
-# shipyard
-Directed acyclic graph controller for Kubernetes and OpenStack control plane life cycle management
+# Shipyard
+Shipyard is the directed acyclic graph controller for Kubernetes and
+OpenStack control plane life cycle management, and a component of the
+Undercloud Platform (UCP)
+
+Shipyard provides the entrypoint for the following aspects of the
+control plane established by the UCP:
+
+<dl>
+    <dt>
+        Designs and Secrets
+    </dt>
+    <dd>
+        Site designs, including the configuration of bare metal host
+        nodes, network design, operating systems, Kubernetes nodes,
+        Armada manifests, Helm charts, and any other descriptors that
+        define the build out of a group of servers enter the UCP via
+        Shipyard. Secrets, such as passwords and certificates use the
+        same mechanism. <br />
+        The designs and secrets are stored in UCP's Deckhand,
+        providing for version history and secure storage among other
+        document-based conveniences.
+    </dd>
+    <dt>
+        Actions
+    </dt>
+    <dd>
+        Interaction with the site's control plane is done via
+        invocation of actions in Shipyard. Each action is backed by
+        a workflow implemented as a directed acyclic graph (DAG) that
+        runs using Apache Airflow. Shipyard provides a mechanism to
+        monitor and control the execution of the workflow.
+    </dd>
+</dl>
+
+## Intgration Points:
+[OpenStack Identity (Keystone)](https://github.com/openstack/keystone)
+provides authentication and support for role based authorization.
+\
+[Apache Airflow](https://airflow.incubator.apache.org/) provides the
+framework and automation of workflows provided by Shipyard.
+\
+[PostgreSQL](https://www.postgresql.org/) is used to persist
+information to correlate workflows with users and history of workflow
+commands.
+\
+[Deckhand](https://github.com/att-comdev/deckhand) supplies storage
+and mangement of site designs and secrets
+\
+[Drydock](https://github.com/att-comdev/drydock) is orchestrated by
+Shipyard to perform bare metal node provisioning.
+\
+[Promenade](https://github.com/att-comdev/promenade) is indirectly
+orchestrated by Shipyard to configure and join Kubernetes nodes
+\
+[Armada](https://github.com/att-comdev/armada) is orchestrated by
+Shipyard to deploy and test Kubernetes workloads
+
+
+
+## Getting Started:
+
+[Shipyard @ Gerrithub](https://review.gerrithub.io/#/q/project:att-comdev/shipyard)
+\
+[Helm chart](https://github.com/att-comdev/aic-helm/tree/master/shipyard)
+
+
+## See also:
+
+[Undercloud Platform (UCP)](https://github.com/att-comdev/ucp-integration)