Add template, use it for relase description

.gitlab-ci.yml

@@ -118,6 +118,6 @@ release_job:
   release:
     # TODO: automated release notes
     name: 'Release $CI_COMMIT_TAG'
-    description: ./CHANGELOG
+    description: ./CHANGELOG.md
     tag_name: '$CI_COMMIT_TAG'
     ref: '$CI_COMMIT_TAG'

CHANGELOG

-

CHANGELOG.md

+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+### Added
+
+- ...
+
+### Changed
+
+- ...
+
+### Deprecated
+
+- ...
+
+### Removed
+
+- ...
+
+### Fixed
+
+- ...
+
+### Security
+
+- ...
+
+## [1.0-alpha1] - 2023-02-24
+
+Initial release.
+