Dimension of Theta Dense Neurons

[arturossouza]

Hi!

I was taking a look on your NBeats implementation and I think that the theta size should be backcast_size + horizon.

I might be mistaken here, but could you explain why you coded as backcast_size + lookback?

Thaaanks!

https://github.com/JonathanBechtel/KerasBeats/blob/ac391acbbffb4c65b312c0059402c1ac8f5eff11/src/kerasbeats/nbeats.py#L43