434 add configuration for automatic changelog generation

[ebma]

This template can be used to create a changelog. Its main purpose is to be used in Spacewalk's release flow to automatically generate a description for the new releases.

To generate the changelog you need to install git-chglog, see here and then run git-chglog -o CHANGELOG.md.

The CI job will run the generation with the latest tag as the argument so that the changelog is only generated containing the changes for the latest release. For example to generate the release notes for release v1.0.3, it will use git-chglog -o CHANGELOG.md v1.0.3...

Closes #434.

[TorstenStueber]

@ebma The description makes it sound like this will be run by CI. But how does it, it looks to me like you did not add this to any GitHub action.

[TorstenStueber]

I don't understand why we use this commit header pattern here. (what even is the commit header?)

[ebma]

AFAIK the commit header is like the first line of your commit which can be 50 characters and the body would be the content you add in new lines.
But we don't need that anyways, so I removed it. Since we squash and merge every feature, it works fine to use the remaining config for merge commits.

[ebma]

My description might have been a little confusing but the CI I'm talking about is run on Gitlab pipelines. That's why I didn't add any changes here. This PR is about adding the necessary configuration so that the CI pipeline can run the commands I put into the description to generate meaningful changelogs.
Changing the Gitlab pipeline is not part of this ticket and something we need to do afterwards.

[TorstenStueber]

Great addition, looks good.

[ebma]

Merging this although the CI failed because the changes of this PR are unrelated to any relevant code and we already know that this is required to fix the CI.