Feature request: add split screen
When viewing a document, it would be very convenience to allow a split view feature where a user can see different parts of the document at the same time. This is useful in a situation where a user is reading a description of a figure that is located on another page. The split screen feature ideally should be able to split vertically or horizontally. It would also be useful if there could be multiple split windows showing more than one parts of the same document. Each split view should allow independent view manipulations (eg. zoom, rotate, etc)