Update dependencies

[tmcinerney]

This PR:

• Bumps the NodeJS version from v10.0.0 to v12.18.0.
• Bumps the versions of electron, electron-packager, and menubar to their latest versions.
• Uses the updated options for Menubar which:
  • Increases the size of the window.
  • Allows resizing, and the scrollbar.
• Removes the use of a webview (which no longer seems to be recommended by the Electron folks), the corresponding index.html, the renderer.js file which hides the scrollbar, and simply uses an index of https://keep.google.com.