doc: Add dependency graph.

Author: freezy

README.md

@@ -2,14 +2,9 @@
 
 *High Definition Render Pipeline support for the Visual Pinball Engine.*
 
-## Goal
+## Where Are We?
 
-This is an [UPM package](https://docs.unity3d.com/Manual/CustomPackages.html) with a dependency to Unity's
-[High Definition Render Pipeline](https://docs.unity3d.com/Packages/[email protected]/manual/index.html).
-If added along with the [VPE package](https://github.com/freezy/VisualPinball.Engine) to a project, VPE will
-use this package for dealing with rendering.
-
-It allows us to implement multiple render pipelines without conflicting dependencies.
+![image](https://user-images.githubusercontent.com/70426/102674479-73491000-4196-11eb-8f7f-68b5d21cdf7e.png)
 
 ## License