Merge branch 'HDRP/add-LightLayer-in-probes' of https://github.com/Unity-Technologies/ScriptableRenderPipeline into HDRP/add-LightLayer-in-probes

README.md

 [High Definition Pipeline Blogpost](https://blogs.unity3d.com/2018/03/16/the-high-definition-render-pipeline-focused-on-visual-quality/)
 
 ## How to use the latest version
-__Note: The Master branch is our current development branch and may not work on the latest publicly available version of Unity. You should always use the latest release tag and latest Unity beta version for testing purposes.__
+__Note: The Master branch is our current development branch and may not work on the latest publicly available version of Unity. To determine which version of SRP you should use with your version of Unity, go to Package Manager (Window > Package Manager) to see what versions of SRP are available for your version of Unity Editor. Then you can search the Tags tab of the Branch dropdown in the SRP GitHub for that tag number.__
 To use the latest version of the SRP, follow the instructions below:
 
 This repository consists of a folder that should be cloned outside the Assets\ folder of your Unity project. We recommend creating a new project to test SRP. Do not clone this repo into an existing project unless you want to break it, or unless you are updating to a newer version of the SRP repo.

com.unity.render-pipelines.high-definition/HDRP/Editor/Lighting/Reflection/HDProbeUI.Drawers.cs

 
         protected static void Drawer_SectionCustomSettings(HDProbeUI s, SerializedHDProbe d, Editor o)
         {
-            EditorGUILayout.PropertyField(d.lightLayers, lightLayersContent);
+            d.lightLayers.intValue = Convert.ToInt32(EditorGUILayout.EnumFlagsField(lightLayersContent, (LightLayerEnum)d.lightLayers.intValue));
 
             EditorGUILayout.PropertyField(d.weight, weightContent);