Fixed release notes formatting to match previous releases

Three bugs in release-notes.js:
- Included non-user-facing emoji commits (e.g. 🔥) instead of only
  💡 🐛 🎨 💄 ✨ 🔒
- Added commit hash links ([hash](url)) not present in old releases
- Stripped PR number references (#1234) that should be kept
- Sort order was inverted (features should sort before bugs)

fixes https://linear.app/ghost/issue/BER-3313