References:
https://arxiv.org/pdf/1912.05911
https://arxiv.org/pdf/1808.03314
https://stanford.edu/~shervine/teaching/cs-230/cheatsheet-recurrent-neural-networks
https://www.d2l.ai/chapter_recurrent-neural-networks
https://www.geeksforgeeks.org/machine-learning/introduction-to-recurrent-neural-network
