Zoom and speaker notes window

[ced42]

Hello,

When two windows are opened (presentation and speaker notes), zoom function on any element works only on one window. I'm wondering if it a bug.

Regards,
Cédric.

[obilodeau]

It would be nice to have the ability to zoom from the speaker notes view and have it synchronized with the presentation view.

[janisdd]

Unfortunately this framework moved away from zooming to elements but now zooms to mouse position...

I just recently needed this feature and implemented it for zooming to elements (I use an older version).
I'm sure I can adapt this to zoom to mouse position.

However, there is the issue with different sizes/aspect ratios of the main and speaker view.

I'll create a PR