Release v0.2.0 (#40)

This PR marks the release of `v0.2.0`. This milestone introduces
significant new functionality compared to `v0.1.0`, including the
addition of the single-step evaluation framework, its integration with
search, and an implementation of PDVN. On top of this, it also includes
several other improvements and bug fixes.

Author: kmaziarz

CHANGELOG.md

@@ -7,6 +7,8 @@ and the project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+## [0.2.0] - 2023-11-21
+
 ### Changed
 
 - Select search hyperparameters depending on which algorithm and single-step model are used ([#30](https://github.com/microsoft/syntheseus/pull/30)) ([@kmaziarz])
@@ -40,8 +42,9 @@ and the project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.
 
 :seedling: Initial public release, containing several multi-step search algorithms and a minimal interface for single-step models.
 
-[Unreleased]: https://github.com/microsoft/syntheseus/compare/v0.1.0...HEAD
+[Unreleased]: https://github.com/microsoft/syntheseus/compare/v0.2.0...HEAD
 [0.1.0]: https://github.com/microsoft/syntheseus/releases/tag/v0.1.0
+[0.2.0]: https://github.com/microsoft/syntheseus/releases/tag/v0.2.0
 
 [@austint]: https://github.com/AustinT
 [@kmaziarz]: https://github.com/kmaziarz