Add CHANGELOG.md

Author: Looooong

CHANGELOG.md

@@ -0,0 +1,15 @@
+## [Unreleased]
+### Added
+- Add `CHANGELOG.md`.
+
+### Fixed
+- Fix typo in `README.md`.
+- Fix performance issue when importing PNG without alpha channel.
+- Fix out of bound access in mipmap generation job.
+
+## [0.1.0] - 2021-07-28
+### Added
+- Implement `AsyncImageLoader`.
+
+[Unreleased]: https://github.com/Looooong/UnityAsyncImageLoader/compare/v0.1.0...HEAD
+[0.1.0]: https://github.com/Looooong/UnityAsyncImageLoader/releases/tag/v0.1.0