Data Supplier - Nested menu items
When creating a DataSupplier plugin - registering each supplier with it's appropriate appellation in the `DataSupplier.registerDataSupplier` creates everything on the same level.

I'm wondering if it's possible to create nested menu structures here

eg 
```
Data Plugin
  > Fruit
     > data set 1
     > data set 2
 > Vedge
    > data set 3
    > data set 4
```
I've tried adding via the _menu_ option in the `manifest.json` file - but no dice