Add image to readme

Author: adam-fowler

README.md

@@ -2,5 +2,8 @@
 
 http://swift-dependency-graph.opticalaberration.com
 
-<p>Display the dependencies or the packages dependent on a swift package in a organisational graph</p>
-<p>The swift dependency graph uses the Swift Package catalog from the <a href="https://swiftpm.co/">SwiftPMLibrary</a> setup by Dave Verwer.</p>
+Display the dependencies or the packages dependent on a swift package in a organisational graph as seen below.
+
+![swift-dependency-graph example](html/images/dependency-graph.png)
+
+The swift dependency graph uses the Swift Package catalog from the <a href="https://swiftpm.co/">SwiftPMLibrary</a> setup by Dave Verwer.