Update README

Author: matthewcpp

README.md

@@ -2,12 +2,12 @@
 This library renders a subset of [ABC Music Notation](http://abcnotation.com/) in Unity.  It is built on the [ABCSharp](https://github.com/matthewcpp/abcsharp) parsing library.
 
 ### Installation
-The easiest way to to use the library is to download the repo as a zip archive and place the extracted directory into your Assets folder.  Optionally the repo can be included as a git submodule in your project.
+The easiest way to to use the library is to install it using the Unity package manager.
 This project requires the installation of the basic TextMeshPro asset package.
 
 ### Basic Usage
 The included sample scene shows basic layout usage.
-The `ABCLayout` prefab serves as a top level container for all the sprites needed to display the score.  The layout will attempt to fill as much as the area defined by the object's RectTransform.
+The `ABCLayout` prefab serves as a top level container for all the sprites needed to display the score.  The layout will attempt to fill as the area defined by the object's RectTransform.
 Abc code is rendering using the `LoadString`, `LoadStream`, or `LoadFile` methods on the `ABCUnity.Layout` class.
 Individual items can have their color set using the `SetItemColor` method.
 
@@ -28,4 +28,14 @@ K:C
 ```
 Appears in the game engine as:
 
-[![score.png](https://i.postimg.cc/T1Fy1dCJ/score.png)](https://matthewcpp.github.io/assets/images/score.png)
+[![score.png](https://i.postimg.cc/T1Fy1dCJ/score.png)](https://matthewcpp.github.io/assets/images/score.png)
+
+### Testing
+The test harness is loacated in the `Runtime/Tests/Test.unity` scene.
+Enter playmode and select the test which to run from the dropdown menu.
+Compare the output with the corresponding baseline file.
+
+### Adding tests
+Create a new abc file in the `Runtime/Resources/Tests` folder that contains the test abc code.  The file should be specified as `testname.abc.txt`.
+Add a new entry to the `testFiles` array in `Runtime/Tests/TestUi.cs`
+Create a new MuseScore file in the `Runtime/Tests/Baselines~` folder that correctly renders the functionality you are testing.