minor #1256 bumping CHANGELOG for 2.13 (weaverryan)

This PR was squashed before being merged into the 2.x branch.

Discussion
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bumping CHANGELOG for 2.13

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| Issues        | None
| License       | MIT

Commits
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cd3fa238f3 bumping CHANGELOG for 2.13

Author: weaverryan

CHANGELOG.md

@@ -1,5 +1,9 @@
 # CHANGELOG
 
+## 2.13.0
+
+-   Change JavaScript package to `type: module`
+
 ## 2.9.0
 
 -   A SwupBundle was added - which allows for integration with symfony/asset-mapper.