Add version link to changelog

Author: dpwiz

ChangeLog.md

@@ -22,6 +22,7 @@ Package moved to https://github.com/haskell-game/aeson-tiled
 
 Initial release.
 
+[0.0.2.1]: https://github.com/haskell-game/aeson-tiled/releases/tag/v0.0.2.1
 [0.0.2.0]: https://github.com/haskell-game/aeson-tiled/releases/tag/v0.0.2.0
 [0.0.1.0]: https://github.com/haskell-game/aeson-tiled/releases/tag/v0.0.1.0
 [0.0.0.1]: https://github.com/haskell-game/aeson-tiled/releases/tag/v0.0.0.1