Release 0.2

[szabo137]

With this issue, we keep track of the workflow for version 0.2.0 release.

Preparation of the release

• tag all PRs that are part of this release by adding them to a milestone named Release-0.2.0.
• Create a release branch release-0.2.0
• Adjust Project.toml on release-0.2.0 by ticking up the version
• Add/Update the file CHANGELOG.md on release-0.2.0 by appending a summary section. This can be done by using the tagged PRs associated with this release.

Releasing procedure

• open PR for merging release-0.2.0 into main with at least one reviewer (who only needs to check the points above, the code additions were reviewed in the respective PRs). The merge must not delete the source branch.
• after the release branch is merged into main, open another PR for merging release-0.2.0 into dev. This can be merged without much review because the relevant changes were already reviewed in the PR release-0.2.0 -> main.
• Registration: go to the issues and search for Release. There, write a comment with at_JuliaRegistrator register() with a real @ to trigger the registration bot opening a PR on Julia's general registry.
• after the registration bot reports back the correct registration, tag the HEAD of main (which should still be the merge commit from the release branch merge) with v0.2.0
• Build a GitHub release from the latest tagged commit on main and add the respective section from CHANGELOG.md to the release notes.

Final remarks

• This issue can also be used as a blueprint for future releases. At some point, we should add this to the contributor's documentation.
• some of the tasks above can be automated, e.g. the tagging and building of the GitHub release can be done using the Julia-TagBot, which is actually a GitHub action.