Auto update and signing

Try electron-forge :

• https://www.electronjs.org/blog/forge-v6-release
• https://www.electronjs.org/docs/latest/tutorial/updates
• https://www.electronjs.org/docs/latest/tutorial/code-signing

Otherwise use electron-builder :

• https://www.electron.build/code-signing
• https://github.com/electron/update-electron-app
• https://www.electron.build/auto-update