Add release action

[kencyke]

The following might be helpful.

• https://github.com/kencyke/lean-project/blob/main/.github/workflows/release-lean.yml
• https://github.com/leanprover-community/lean-release-tag
  • https://github.com/RemyDegenne/brownian-motion/blob/master/.github/workflows/create-release.yml
  • https://github.com/google-deepmind/formal-conjectures/blob/main/.github/workflows/lean-release-tag.yml
• https://github.com/step-security/action-gh-release
• https://zenn.dev/meihei/articles/01923ca5-a64f-7330-86b4-de994cf98a30