Add release notes for #669

Author: NickCraver

docs/Releases.md

@@ -9,6 +9,7 @@ This page tracks major changes included in any update starting with version 4.0.
 - **New**:
   - Support for strict CSP (dynamic inline styles removed) ([#634](https://github.com/MiniProfiler/dotnet/pull/634) - thanks [rwasef1830](https://github.com/rwasef1830))
   - Moved .NET Core to `net8.0` with no `Newtonsoft.Json` dependency ([#641](https://github.com/MiniProfiler/dotnet/pull/641) & [#679](https://github.com/MiniProfiler/dotnet/pull/679))
+  - Add support for additional client-side headers in custom implementations ([#669](https://github.com/MiniProfiler/dotnet/pull/669) - thanks [Breederveld](https://github.com/Breederveld))
 - **Fixes/Changes**: 
   - Upgraded MongoDB driver, allowing automatic index creation and profiler expiration ([#613](https://github.com/MiniProfiler/dotnet/pull/613) - thanks [IanKemp](https://github.com/IanKemp))
   - Fixed [#652](https://github.com/MiniProfiler/dotnet/issues/652): Respect `PopupDecimalPlaces` in all cases ([#655](https://github.com/MiniProfiler/dotnet/pull/655))