H3 RNN Encoder available values mentioned twice for cell_type

[mhabedank]

The docs repeat the information, see here.

cell_type (default: rnn) : The type of recurrent cell to use. Available values are: rnn, lstm, lstm_block, lstm, ln, lstm_cudnn, gru, gru_block, gru_cudnn.
For reference about the differences between the cells please refer to PyTorch's documentation.
We suggest to use the block variants on CPU and the cudnn variants on GPU because of their increased speed.
Options: rnn, lstm, lstm_block, ln, lstm_cudnn, gru, gru_block, gru_cudnn.