Create release.yml file for automatic release notes generation (#1925)

* Create release.yml file for automatic release notes generation

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`, `feature`, `enhancement`, `bug`, `docs`, `ci`, `testing`, `dependency`, `maintenance` and `packaging`. The last four are grouped in the changelog under _Maintenance 🔧_.

See [Automatically generated release notes](https://docs.github.com/en/repositories/releasing-projects-on-github/automatically-generated-release-notes).

* release.yml: Add experimental category for release note generation

Author: EwoutH

.github/release.yml

@@ -0,0 +1,34 @@
+# Docs: https://docs.github.com/en/repositories/releasing-projects-on-github/automatically-generated-release-notes
+changelog:
+  exclude:
+    labels:
+      - ignore-for-release
+  categories:
+    - title: ⚠️ Breaking changes
+      labels:
+        - breaking
+    - title: 🧪 Experimental features
+      labels:
+        - experimental
+    - title: 🎉 New features added
+      labels:
+        - feature
+    - title: 🛠 Enhancements made
+      labels:
+        - enhancement
+    - title: 🐛 Bugs fixed
+      labels:
+        - bug
+    - title: 📜 Documentation improvements
+      labels:
+        - docs
+    - title: 🔧 Maintenance
+      labels:
+        - ci
+        - testing
+        - dependency
+        - maintenance
+        - packaging
+    - title: Other changes
+      labels:
+        - "*"