Add changelog

Author: albertomercurio

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Improve efficiency of `bloch_redfield_tensor` by avoiding unnecessary conversions. ([#509])
 - Support `SciMLOperators v1.4+`. ([#470])
 - Fix compatibility with `Makie v0.24+`. ([#513])
+- Add support to ForwardDiff.jl for `sesolve` and `mesolve`. ([#515])
 
 ## [v0.33.0]
 Release date: 2025-07-22
@@ -274,3 +275,4 @@ Release date: 2024-11-13
 [#507]: https://github.com/qutip/QuantumToolbox.jl/issues/507
 [#509]: https://github.com/qutip/QuantumToolbox.jl/issues/509
 [#513]: https://github.com/qutip/QuantumToolbox.jl/issues/513
+[#515]: https://github.com/qutip/QuantumToolbox.jl/issues/515