Update support platform doc for Apple M1 issue (actions#1057)

* apple M1 issue

* Update docs/start/envosx.md

Co-authored-by: Ross Brodbeck <hross@users.noreply.github.com>

* Update docs/start/envosx.md

Co-authored-by: Ross Brodbeck <hross@users.noreply.github.com>

Co-authored-by: Ross Brodbeck <hross@users.noreply.github.com>

docs/start/envosx.md

@@ -5,6 +5,12 @@
 ## Supported Versions
 
   - macOS High Sierra (10.13) and later versions
+
+## Apple Silicon M1
 
+The runner is currently not supported on devices with an Apple M1 chip.  
+We are waiting for official .NET support. You can read more here about the [current state of support here](https://github.com/orgs/dotnet/projects/18#card-56812463).
+Current .NET project board about M1 support:
+https://github.com/orgs/dotnet/projects/18#card-56812463
 
 ## [More .Net Core Prerequisites Information](https://docs.microsoft.com/en-us/dotnet/core/macos-prerequisites?tabs=netcore30)