Unable to implement multiple branches with `forkTask`

[matt-sanders]

Hi 👋

I think that perhaps the implementation of forkTask limits the developer to creating a single branch.

The fork example in the docs shows that forkTasks should be List[List[Task]] but I believe the signature here limits this to [List[Task]] ( note this is an array with a single item, not a List[] ).

Am I reading this correct? I can't seem to get forkTask() to create the output I'm after, but not sure if that's user error or an issue with the library.

In the meantime I'm implementing this manually.