Update runtime.md for Preview 1 (#10229)

* Update runtime.md for Preview 1

* update

Author: jamesmontemagno

release-notes/11.0/preview/preview1/runtime.md

@@ -1,9 +1,3 @@
 # .NET Runtime in .NET 11 Preview 1 - Release Notes
 
-.NET 11 Preview 1 includes new .NET Runtime features & enhancements.
-
-This Preview 1 release does not introduce new .NET Runtime features.
-
-.NET Runtime updates in .NET 11:
-
-- [What's new in .NET 11](https://learn.microsoft.com/dotnet/core/whats-new/dotnet-11/overview) documentation
+Release notes are in progress. In the meantime see all merged pull requests on [dotnet/runtime](https://github.com/dotnet/runtime/pulls?q=sort%3Aupdated-desc+is%3Apr+milestone%3A11.0.0+is%3Amerged).