Automatic Release Notes (#731)

This patch configures the release notes which can be automatically
generated by GitHub to have a better structure based on labels assigned
to pull requests.

The release notes can be generated either by clicking the „generate
release notes“ button when creating a new release manually, or this can
be part of a workflow which completely automates cutting a release.

The generated release notes would look like this:
- https://github.com/opencast/opencast-editor/releases/tag/2022-10-06

Automating the whole release could look like this (here is just
generates draft releases which still have to be approved manually):
- https://github.com/opencast/opencast-editor/blob/main/.github/workflows/create-release.yml

.github/release.yml

@@ -0,0 +1,33 @@
+changelog:
+
+ exclude:
+ authors:
+ - dependabot
+ - dependabot[bot]
+
+ categories:
+ - title: Security Fixes
+ labels:
+ - type:security
+
+ - title: New Features
+ labels:
+ - type:feature
+
+ - title: Usability and Accessibility
+ labels:
+ - type:usability
+ - type:accessibility
+ - type:visual-clarity
+
+ - title: Bug Fixes
+ labels:
+ - type:bug
+
+ - title: Documentation
+ labels:
+ - type:documentation
+
+ - title: Other Changes
+ labels:
+ - "type:*"