Update CHANGELOG.md

Author: AdrianSosic

CHANGELOG.md

@@ -17,10 +17,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Basic deserialization tests using different class type specifiers
 - `GammaPrior`, `HalfCauchyPrior`, `NormalPrior`, `HalfNormalPrior`, `LogNormalPrior`
   and `SmoothedBoxPrior` can now be chosen as lengthscale prior
+- `KernelFactory` protocol enabling flexible construction of kernels
+- Preset mechanism for Gaussian process surrogates
 
 ### Changed
 - Reorganized acquisition.py into `acquisition` subpackage
 - Reorganized simulation.py into `simulation` subpackage
+- Reorganized gaussian_process.py into `gaussian_process` subpackage
 - Acquisition functions are now their own objects
 - `acquisition_function_cls` constructor parameter renamed to `acquisition_function`
 - User guide now explains the new objective classes