[TASK] Add changelog entries since 4.0.0-alpha1 (#90)

Author: oliverklee

CHANGELOG.md

@@ -4,21 +4,20 @@ All notable changes to this project will be documented in this file.
 This project adheres to [Semantic Versioning](https://semver.org/).
 
 
-## 4.0.0 (unreleased)
+## x.y.z
 
 ### Added
-
+- REST API endpoint for getting list details (#89)
+- System tests for the test and dev environment (#81)
+- REST action for getting all subscribers for a list (#83)
 
 ### Changed
 
-
 ### Deprecated
 
-
 ### Removed
 
-
 ### Fixed
-
+- Always truncate the DB tables after an integration test (#86)
 
 ### Security