Update runtime.md for RC 2 scaffold (#10097)

Author: jongalloway

release-notes/10.0/preview/rc2/runtime.md

@@ -1,15 +1,23 @@
 # Runtime updates in .NET 10 Release Candidate 2
 
+Here's a summary of what's new in Runtime in this RC 2 release:
+
+- [Feature](#feature)
+
+## Feature
+
+Feature summary
+
 This release was focused on quality improvements as we near general availability of .NET 10. It is covered by a go-live license, and we encourage developers today to try it out and provide feedback on anything that you find in your development so we can incorporate any additional enhancements into the final release.
 
 Runtime updates in .NET 10 Release Candidate 2:
 
-* [What's new in the .NET Runtime in .NET 10](https://learn.microsoft.com/dotnet/core/whats-new/dotnet-10/overview) documentation
-* (Changelog link to be updated when tag is available)
+- [What's new in the .NET Runtime in .NET 10](https://learn.microsoft.com/dotnet/core/whats-new/dotnet-10/overview) documentation
+- (Changelog link to be updated when tag is available)
 
 .NET 10 RC 2:
 
-* [Discussion](https://aka.ms/dotnet/10/rc2)
-* [Release notes](README.md)
-* [SDK release notes](sdk.md)
-* [Libraries release notes](libraries.md)
+- [Discussion](https://aka.ms/dotnet/10/rc2)
+- [Release notes](README.md)
+- [SDK release notes](sdk.md)
+- [Libraries release notes](libraries.md)