docs: Fix link

Author: Stranger6667

CHANGELOG.md

@@ -355,7 +355,7 @@
 
 - Initial public release
 
-[Unreleased]: https://github.com/Stranger6667/css-inline/compare/rust-v0.11.2...HEAD
+[Unreleased]: https://github.com/Stranger6667/css-inline/compare/rust-v0.12.0...HEAD
 [0.12.0]: https://github.com/Stranger6667/css-inline/compare/rust-v0.11.2...rust-v0.12.0
 [0.11.2]: https://github.com/Stranger6667/css-inline/compare/rust-v0.11.1...rust-v0.11.2
 [0.11.1]: https://github.com/Stranger6667/css-inline/compare/rust-v0.11.0...rust-v0.11.1