Fix changelog

Author: murny

CHANGELOG.md

@@ -7,7 +7,7 @@ and releases in Jupiter project adheres to [Semantic Versioning](http://semver.o
 
 New entries in this file should aim to provide a meaningful amount of information in order to allow people to understand the change purely by reading this file, without relying on links to possibly-impermanent sources like Pull Request descriptions or issues.
 
-## [Unreleased
+## [Unreleased]
 
 ### Added
 - Migrate Webpacker to Esbuild [PR#3320](https://github.com/ualbertalib/jupiter/pull/3320)