Added highlight description of the changes.

Author: timcassell

docs/_changelog/header/v0.14.0.md

@@ -1,5 +1,7 @@
 ## Highlights
 
+* The default build toolchains have been updated to pass `IntermediateOutputPath`, `OutputPath`, and `OutDir` properties to the `dotnet build` command. This change forces all build outputs to be placed in a new directory generated by BenchmarkDotNet, and fixes many issues that have been reported with builds. You can also access these paths in your own `.csproj` and `.props` from those properties if you need to copy custom files to the output.
+
 ## Bug fixes
 
 * Fixed multiple build-related bugs including passing MsBuildArguments and .Net 8's `UseArtifactsOutput`.