[ GitHub ] Add release.yml to format automatically generated release notes

[L-TChen]

I just realised that the automatically generated release notes can be configured according to this.

At present, the release note for the latest commit is automatically generated, but it could be more informative. It includes all PRs, even those with labels like not-in-changelog that are clearly not very interesting. So, I am adding the release.yml to exclude those PRs labelled not-in-changelog, type, and so on.

We may take advantage of organising PRs into sections based on their labels, such as a section for bug fixes and another for type: enhancement. On the other hand, perhaps I shouldn't over-engineer the format of automatically generated notes, so I shall add this release.yml as it is and refine the configuration gradually.

[andreasabel]

Great stuff!

[andreasabel]

Should this list be the same as the CIFM one:

agda/src/release-tools/closed-issues-for-milestone/Main.hs

Lines 115 to 146 in 1c449e2

	labelsNotInChangelog :: Set Label
	labelsNotInChangelog = Set.fromList
	[ "Makefile"
	, "agda-bisect"
	, "bug-tracker"
	, "closed-issues-for-milestone"
	, "devx"
	, "debug"
	, "documented-in-changelog"
	, "faq"
	, "fix-agda-whitespace"
	, "haddock"
	, "hTags"
	, "infra: github workflows"
	, "infra: test suite"
	, "maculata"
	, "not-in-changelog"
	, "refactor"
	, "regression on master"
	, "release"
	, "repository"
	, "status: abandoned"
	, "status: duplicate"
	, "status: invalid"
	, "status: wontfix"
	, "status: working-as-intended"
	, "style"
	, "travis"
	, "type: question"
	, "type: task"
	, "typo"
	]

If yes, maybe the latter should be read from the new YAML file to avoid duplication.

[L-TChen]

You're right -- I will revise it.