Add missing entry in the changelog about the KOKKOS_DEDUCTION_GUIDE m…

…acro (kokkos#7397)

* Add missing entry in the changelog about the KOKKOS_DEDUCTION_GUIDE macro

* Review from masterleinad

* Improve typesetting [CI skip]

* Moved Entry to enhancements

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Co-authored-by: Damien L-G <dalg24+github@gmail.com>
Co-authored-by: Christian Trott <crtrott@sandia.gov>

CHANGELOG.md

@@ -57,6 +57,7 @@
 * SIMD: Allow flexible vector width for 32 bit types [\#6802](https://github.com/kokkos/kokkos/pull/6802)
 * Updates for `Kokkos::Array`: add `kokkos_swap(Array<T, N>)` specialization [\#6943](https://github.com/kokkos/kokkos/pull/6943), add `Kokkos::to_array` [\#6375](https://github.com/kokkos/kokkos/pull/6375),  make `Kokkos::Array` equality-comparable [\#7148](https://github.com/kokkos/kokkos/pull/7148)
 * Structured binding support for `Kokkos::complex` [\#7040](https://github.com/kokkos/kokkos/pull/7040)
+* Introduce `KOKKOS_DEDUCTION_GUIDE` macro to allow for portable user-defined deduction guides [\#6954](https://github.com/kokkos/kokkos/pull/6954)
 
 ### Build System Changes
 * Do not require OpenMP support for languages other than CXX [\#6965](https://github.com/kokkos/kokkos/pull/6965)