Animate with css instead of js

[wpsumo]

Describe the feature you'd like to see included.
1) It would be nice if we could pick to animate with transform and CSS instead of relying on JS to show menu items. Applies to both drop-down and off-canvas on mobile.

Would reduce the use of aos.js and move towards less js. If enabled css we add a feature to the animate with css instead of js in oxygen. As in many cases aos.js is not needed to archive, and then we cna disable the lib for users who do not need. Right now I load the whole lib for the pro menu only which can be done with css.