Make avatar buildable, and improve examples:

- Surround example code with UNITY_EDITOR condition
- Change assembly definition to depend on VRC
- Improve Example 3: Make it animate a wedge
- Improve ExampleManual Placing States: Add zero argument overload

Examples/AacExample.cs

@@ -1,4 +1,5 @@
-using System;
+#if UNITY_EDITOR
+using System;
 using AnimatorAsCode.V0;
 using UnityEditor;
 using UnityEngine;
@@ -110,3 +111,4 @@ namespace AnimatorAsCodeFramework.Examples
         }
     }
 }
+#endif