feat: start of actual changelog

Author: samrose

.github/workflows/ami-release-nix.yml

@@ -122,7 +122,7 @@ jobs:
       - name: Generate Changelog
         if: steps.process_release_version.outputs.is_release == 'true'
         run: |
-          nix run nixpkgs#git-cliff -- --tag-pattern "^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]{3}(-orioledb)?$" --unreleased --tag "${{ steps.process_release_version.outputs.version }}" -o CHANGELOG.md
+          nix run nixpkgs#git-cliff -- --tag-pattern "^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]{3}(-orioledb)?$" --unreleased --tag "${{ steps.process_release_version.outputs.version }}" --prepend CHANGELOG.md
 
       - name: Commit and push changelog
         if: steps.process_release_version.outputs.is_release == 'true'