message: DOC: document new RAJA-based BVH in release notes
diff: @@ -10,6 +10,11 @@ The Axom project release numbers follow [Semantic Versioning](http://semver.org/
  ## [Unreleased] - Release date yyyy-mm-dd
  ### Added
  +- Added a new implementation of the Bounding Volume Hierarchy(BVH) spatial
  + acceleration data-structure to spin. The new BVH implementation relies on RAJA
  + and allows for constructing and using the BVH sequentially or in parallel on
  + the CPU or in parallel on the GPU. The new implementation is available only
  + when Axom is compiled with RAJA and Umpire support.
  - Added Umpire and RAJA to the spack build.
  - Centralized Axom's memory management functions in a separate header and extended them
  to use Umpire when enabled.
  