message: Add CHANGELOG entry for Decimal{,256}::from_atomics
diff: @@ -18,6 +18,7 @@ and this project adheres to
  `Uint512::from_uint256`.
  - cosmwasm-std: New getters `Decimal{,256}::atomics()` and
  `Decimal{,256}::decimal_places()`.
  +- cosmwasm-std: New constructors `Decimal{,256}::from_atomics`.
  - cosmwasm-std: New `Uint128::checked_pow`.
  ### Changed
  