Include vs import when using generics

[giaco]

mixin desn't work, I get same compile time error, but it compiles successfully 
using `bind` instead.
    
    
    import arraymancer
    
    proc bar*[V]() =
      bind newTensor
      
      discard newTensor[float32](0).asType(V)
    
    
    Run

I think the answer lies in understanding this.

<https://nim-lang.org/docs/manual.html#generics-delegating-bind-statements>

But an explanation would be appreciated. Thanks