• Handle open-url event: support "deep-linking" e.g. for mailto links (PR #1418, fix #1412)
• Bump default Electron to 18.3.1 (from 18.2.0), with security fixes:
  https://github.com/electron/electron/releases/tag/v18.2.1
  https://github.com/electron/electron/releases/tag/v18.2.2
  https://github.com/electron/electron/releases/tag/v18.2.3
  https://github.com/electron/electron/releases/tag/v18.2.4
  https://github.com/electron/electron/releases/tag/v18.3.0
  https://github.com/electron/electron/releases/tag/v18.3.1
• Update dependencies
• Docs: {API, README, CATALOG}.md cleanups