Simple 3d slicer

• Implemented slicer function for viewing slices in a single arbitrary dimension with slider
• Implemented orthogonal function for viewing slices in all three dimensions with slider

qim3d/viz/img.py

@@ -437,7 +437,7 @@ def slicer(
         continuous_update=True,
     )
     slicer_obj = widgets.interactive(_slicer, position=position_slider)
-    slicer_obj.layout = widgets.Layout(align_items="center")
+    slicer_obj.layout = widgets.Layout(align_items="flex-start")
 
     return slicer_obj