[FEATURE REQUEST] Implement LSTM layer type

[LdDl]

Is your feature request related to a problem? Please describe. There is not LSTM layer type (LSTM - Long Short Term Memory).

Describe the solution you'd like and provide pseudocode examples if you can Implement it and create proper docs

Describe alternatives you've considered and provide pseudocode examples if you can nope

Additional context It would be cool to have an example of LSTM also.

[LdDl]

Well, I guess I'll struggle with it for a big amount of time. It would be awesome if someone can help me with this layer type.

[LdDl]

#9 Should be closed first, since Embedd layer is used in LSTM