v3.14.0

Features

• Dragging into the gap between an open folder and its first child now supports a
  horizontal slide, matching how items and closed folders already behave. Sliding
  right still drops the node as the folder's first child (the previous behavior);
  sliding left drops it as a sibling — or grandsibling — of the folder, bounded by
  the folder's ancestor chain. computeDrop previously hard-coded this gap to
  "first child," so the level was pinned and the slide never engaged (issue #330). (#378)