Adhere to Keep a Changelog (typst-community#24)

Author: sebmestrallet

CHANGELOG.md

@@ -1,13 +1,46 @@
-# [unreleased](https://github.com/<author>/<my-package>/releases/tag/<the-tag>)
-## Added
+# Changelog
 
-## Removed
+All notable changes to this project will be documented in this file.
 
-## Changed
+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).
 
-## Migration Guide from v0.1.X
+## [Unreleased]
 
----
+<details>
+<summary>Migration guide from v0.1.X</summary>
 
-# [v0.1.0](https://github.com/<author>/<my-package>/releases/tag/v0.1.0)
-Initial Release
+<!-- Write migration guide here -->
+
+</details>
+
+### Added
+
+### Changed
+
+### Deprecated
+
+### Removed
+
+### Fixed
+
+### Security
+
+## [0.1.0] - 2025-01-01
+
+### Added
+
+<!-- Describe the feature set of the initial release here -->
+- 
+- 
+- 
+
+<!--
+    Below are the target URLs for each version
+    You can link version numbers (in level-2 headings)
+    to the corresponding tag on GitHub, or the diff
+    in comparison to the previous release
+-->
+
+[Unreleased]: https://github.com/<author>/<my-package>/compare/v0.1.0...HEAD
+[0.1.0]: https://github.com/<author>/<my-package>/releases/tag/v0.1.0