update CHANGELOG.md for v2.0a1

CHANGELOG.md

@@ -6,7 +6,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 
-## [v2.0a1] - Unreleased
+## [2.0a1] - 2024-07-17
 
 This release creates the libcasm-clexmonte cluster expansion based Monte Carlo module. It includes:
 
@@ -15,11 +15,6 @@ This release creates the libcasm-clexmonte cluster expansion based Monte Carlo m
 - Metropolis and N-fold way implementations
 - Support for customizing sampling and analysis functions
 
-The distribution package libcasm-clexmonte contains several Python packages of use for configuration comparison and enumeration:
-
-- libcasm.clexmonte.canonical
-- libcasm.clexmonte.semigrand_canonical
-- libcasm.kinetic
-- TODO
+The distribution package libcasm-clexmonte contains a Python package (libcasm.clexmonte) that provides an interface to Monte Carlo simulation methods implemented in C++. The libcasm.clexmonte.MonteCalculator class currently provides access to simulations in the canonical and semi-grand canonical ensemble and will be expanded in the next releases to include additional methods.
 
 This package may be installed via pip install, using scikit-build, CMake, and pybind11. This release also includes usage examples and API documentation, built using Sphinx.