Update MRTK2 README (#11243)

Update README.md

Update info regarding the MRTK2 tutorial.

Author: MaxWang-MS

README.md

@@ -27,7 +27,7 @@ MRTK-Unity is a Microsoft-driven project that provides a set of components and f
 
 If you're new to MRTK or Mixed Reality development in Unity, **we recommend you start at the beginning of our** [Unity development journey](https://docs.microsoft.com/windows/mixed-reality/unity-development-overview?tabs=mrtk%2Chl2) in the Microsoft Docs. The Unity development journey is specifically tailored to walk new developers through the installation, core concepts, and usage of MRTK.
 
-| IMPORTANT: The Unity development journey currently uses **MRTK version 2.7.2**, **Mixed Reality OpenXR plugin version 1.0.0** and **Unity 2020.3.8+**. |
+| IMPORTANT: The Unity development journey currently uses **MRTK version 2.8.2**, **Mixed Reality OpenXR plugin version 1.6.0** and **Unity 2020.3.42+**. |
 | --- |
 
 If you're an experienced Mixed Reality or MRTK developer, check the links in the next section for the newest packages and release notes.