Update changelog

Author: w1th0utnam3

CHANGELOG.md

@@ -5,6 +5,8 @@ The following changes are present in the `main` branch of the repository and are
  - Py: Major refactor of the Python bindings, interface is simplified and more "pythonic"
    - Merged distinct F64/F32 classes and functions and infer data type automatically
    - Nearly all inputs and outputs are now zero-copy (e.g. mesh vertices and faces can be accessed as attributes without copies)
+ - Lib: Enforce that `Index` types are signed integers implementing the `num_traits::Signed` trait. Currently the reconstruction does not work (correctly) with unsigned integers.
+ - Lib: Make most fields of `SurfaceReconstruction` public
  - CLI: Add some tests for the `reconstruction_pipeline` function
  - CLI: Fix post-processing when particle AABB filtering is enabled
  - Lib: Support subdomain "ghost particle" margins to be up to the size of the subdomain itself (previously limited to half the size)