Add .NET containers preview 4 release notes

Author: lbussell

release-notes/11.0/preview/preview4/containers.md

@@ -1,5 +1,9 @@
 # Containers in .NET 11 Preview 4 - Release Notes
 
-There are no new features or improvements in Containers in this release.
+Here's a summary of what's new for .NET container images in this Preview 3 release:
 
-_This component lives outside the VMR; the component team will replace this stub with their preview content._
+## .NET 11 SDK container images include PowerShell 7.7
+
+The SDK container images now include PowerShell 7.7 ([dotnet/dotnet-docker#7167](https://github.com/dotnet/dotnet-docker/pull/7167)).
+PowerShell 7.7 is built on .NET 11.
+For more details, see [What's New in PowerShell 7.7](https://learn.microsoft.com/powershell/scripting/whats-new/what-s-new-in-powershell-77).