Add changelog entry for added velocity systems and new cmake tester result update variable.

Author: MFraters

CHANGELOG.md

@@ -11,6 +11,8 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased]
 ### Added
+- Added a velocities system where each feature can define a velocity field and the gwb can return the resulting velocity field. \[Menno Fraters; 2024-10-20; [#761](https://github.com/GeodynamicWorldBuilder/WorldBuilder/pull/761)\]
+- There is now a CMake variable to automatically update the reference files for failed tests (gdb-dat and gwb-grid tests) \[Menno Fraters; 2024-10-20; [#761](https://github.com/GeodynamicWorldBuilder/WorldBuilder/pull/761)\]
 
 ## Changed