Reorganize page by drag-n-drop to ToC

[Hector Z]

I've been using zim for many years (linux) and love that it is simple and doesn't have excessive features, so I don't waste time with endless tweaking. That said, there are a few features that I started feeling would be very desirable to have.

1. Move sections in ToC
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One of them is to be able to change the order of the items in the TOC tab by drag and drop. Currently, the only option is to demote/promote and expand/collapse. What I propose is to be able to click one or more items in the TOC and drag them to another position.

The expected result would be that those very blocks were moved in the actual page.

This would be a big time-saver when restructuring documents.

2. Drop paragrahs to ToC
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One of them is to be able to drag text from the main window into a section from the TOC left tab. The desired outcome would be for the text to disappear from where it was and be moved to the end of the TOC section I selected.

This would be an **enormous** time-saver. For example, when organizing big chunks of lose notes.

A user can create empty sections at the top of the page and then proceed to drag actual text blocks to drop in the TOC item at the left.