… says the DT manual.
The items can then be moved with the mouse. If you prefer to use the keyboard, you can try these simple Keyboard Maestro (KM) or BetterTochTool (BTT) macros.
⌘+Arrow Up/Down moves an item one line up or down. The document does not have to be highlighted for this. The shortcut can of course be changed. The macros work with font size 18, otherwise they need to be adapted.
The macros are far from perfect 
and KM is unfortunately slower than BTT, but sometimes I prefer the keyboard to the mouse. Use it at your own risk 
BTT Macros
Move Item DOWN.bttpreset.zip (3.3 KB)
Move Item UP.bttpreset.zip (3.3 KB)
KM Macors
Move Item DOWN.kmmacros.zip (5.3 KB)
Move Item UP.kmmacros.zip (5.3 KB)