Add changelog

Author: albertomercurio

CHANGELOG.md

@@ -7,6 +7,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased](https://github.com/qutip/QuantumToolbox.jl/tree/main)
 
+- Change the structure of block diagonalization functions, using `BlockDiagonalForm` struct and changing the function name from `bdf` to `block_diagonal_form`. ([#349])
+
 
 ## [v0.24.0]
 Release date: 2024-12-13
@@ -50,6 +52,7 @@ Release date: 2024-11-13
 [v0.22.0]: https://github.com/qutip/QuantumToolbox.jl/releases/tag/v0.22.0
 [v0.23.0]: https://github.com/qutip/QuantumToolbox.jl/releases/tag/v0.23.0
 [v0.23.1]: https://github.com/qutip/QuantumToolbox.jl/releases/tag/v0.23.1
+[v0.24.0]: https://github.com/qutip/QuantumToolbox.jl/releases/tag/v0.24.0
 [#86]: https://github.com/qutip/QuantumToolbox.jl/issues/86
 [#139]: https://github.com/qutip/QuantumToolbox.jl/issues/139
 [#292]: https://github.com/qutip/QuantumToolbox.jl/issues/292
@@ -66,3 +69,4 @@ Release date: 2024-11-13
 [#342]: https://github.com/qutip/QuantumToolbox.jl/issues/342
 [#346]: https://github.com/qutip/QuantumToolbox.jl/issues/346
 [#347]: https://github.com/qutip/QuantumToolbox.jl/issues/347
+[#349]: https://github.com/qutip/QuantumToolbox.jl/issues/349