Add RWKV models

[guangyusong]

Changes:

Added support for RWKV model family.

Related links:

Paper: https://arxiv.org/abs/2305.13048 Github: https://github.com/BlinkDL/RWKV-LM

Screenshots:

Model list:

Sample generation:

[salesforce-cla[bot]]

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[bdqnghi]

thank you. The RWKV model family looks very nice. However, they are not really code learning models, do you have the checkpoints related to coding tasks?

[guangyusong]

The RWKV model family should have a similar data split as GPT-J. We anticipate releasing a model that's more adept at coding tasks in the near future.