Merge pull request #9860 from keveleigh/update-readme

Update UPM Readme.md

Author: David Kline

UPM/Documentation~/README.md

@@ -1,4 +1,4 @@
 # Microsoft Mixed Reality Toolkit
 
-[Getting Started](https://docs.microsoft.com/en-us/windows/mixed-reality/develop/unity/mrtk-getting-started)
-[MRTK Documentation on GitHub](https://microsoft.github.io/MixedRealityToolkit-Unity/README.html)
+[Getting Started](https://docs.microsoft.com/windows/mixed-reality/develop/unity/mrtk-getting-started)
+[MRTK Documentation](https://docs.microsoft.com/windows/mixed-reality/mrtk-unity)