Add release.yml file for automatic release notes generation

[EwoutH]

This PR adds a configuration file .github/release.yml that lets GitHub automatically draft release notes based on the labels attached to PRs that will be included in that release. These drafted release notes can form a consistent basis for our changelog and manually expanded with context for certain PRs if needed.

The currently proposed labels are breaking, experimental, feature, enhancement, bug, docs, ci, testing, dependency, maintenance and packaging. The last four are grouped in the changelog under Maintenance 🔧.

For this to work nicely, it's important that all merged PRs have one of these labels attached to them and that the PR titles are sufficiently descriptive.

As an example, we use this over at Mesa to create pretty release notes:

• All our merged PRs are labeled with one of the labels listed in release.yml (and have a clear, descriptive title).
• A release can now look like this.
• The "What's Changed" part is fully automated generated by pressing the "Generate release notes" button when creating a new release.

For further reference, see Automatically generated release notes.

[toruseo]

thanks, will try

and glad to see that "measure-coverage" test is successfully skiped