Issue: AJAX Previews

One of the best features of VaultWiki 3, according to random internet posts, was the popup when hovering over wiki links that showed a snippet of text from the target page. This feature has not been present in VaultWiki 4 although there is a toggle setting for it.

Completed for the next release. The new implementation is much simpler and less error-prone on the Javascript side than its VW3 counterpart.