\Litestep\personal\popup.rc

Scroll down to line 86 where you'll see...

;*Popup "manage windows" Folder
; *Popup "tile horizontal" !TileWindowsH
; *Popup "tile vertical" !TileWindowsV
; *Popup "cascade" !CascadeWindows
; *Popup "minimize all" !MinimizeWindows
; *Popup "restore all" !RestoreWindows
;*Popup ~Folder

Uncomment those. Or, make your own !MinimizeWindows entry.