provide webFrame access

[whyboris]

now you can change zoom factor from within your components:

this.electronService.webFrame.setZoomFactor(0.8);

Please let me know if this was left out intentionally.

[maximegris]

No it wasn't.
I only added an example of how to import and use node/electron modules.
I'll merge your PR, one more example cost nothing 👍

[whyboris]

Great!
I used the webFrame.zoomFactor in my app -- a very useful feature to have in an app that may need to run on a 4k screen (where the UI becomes too-tiny-to-see from far away).
Thank you for the project and the ongoing work you do!