message: DOC: doc BVH updates to use supplied allocator
  Document updates to the BVH that enable using a supplied allocator.
diff: @@ -10,6 +10,11 @@ The Axom project release numbers follow [Semantic Versioning](http://semver.org/
  ## [Unreleased] - Release date yyyy-mm-dd
  ### Added
  +- Added the ability to specify a user-supplied allocator ID to use with the
  + BVH. This allows the application to use a device allocator for the BVH and
  + avoid use of UM on the GPU, which can hinder perfomrmance, or use a pool
  + allocator to mitigate the latencies associated with allocation/deallocation.
  + The allocator ID is specified as an optional argument to the BVH constructor.
  - Added new CMake option, `AXOM_ENABLE_ANNOTATIONS`, to enable/disable code
  annotations in Axom. Default is OFF.
  - Added Axom annotation macros. The macros can be used to annotate functions,
  