Update changelog

TravisCardwell · TravisCardwell · commit 780d35b1ad0f · 2020-09-12T19:50:19.000+09:00
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -24,7 +24,7 @@ following conventions:
 
 [KaC]: <https://keepachangelog.com/en/1.0.0/>
 
-## Unreleased
+## 0.4.0.0 (2020-09-12)
 
 ### Breaking
 
