Auto scroll not happening when I drag something and approach an edge (bottom) in the viewport

**`react-sortable-tree` is a wonderful library. I'm loving it!**

My virtualized sortable tree doesn't auto-scroll when I drag an item to the bottom of the viewport. Requesting clarification on how to enable it.

Auto-scroll on drag was introduced in v0.1.2 according to this issue: https://github.com/frontend-collective/react-sortable-tree/issues/3

Here is my SortableTree.
```
true}
canNodeHaveChildren={node => true}
treeData={tree.items}
treeNodeRenderer={props => }
nodeContentRenderer={props => (

)}
/>
```
The `Node` has a drag handle like so:
```
const handle = connectDragSource(
(

), {
dropEffect: 'copy',
},
);
```
---
When I drag the handle icon, I expect the virtual list component to auto-scroll as I approach the bottom edge of the viewport. Its not happening.

Here is a screen recording of what I'm trying to do. Please advice on how to approach this.
If I need to add more information or context, please let me know in comments. Thanks in advance!

---