Add Cryptography Guidelines, CryptoGotchas, and cryptocoding

[samuel-lucas6]

Cryptography Guidelines is a document I'm working on that outlines recommendations for cryptographic algorithm choices and parameters as well as important implementation details. I'm currently in the process of mentioning algorithms like SHAKE, AEGIS, and Rocca. I'd also like to add a discussion about SHA2 vs SHA3, rearrange some recommendations, and so on.

CryptoGotchas outlines counter-intuitive 'gotchas' in cryptography. A lot of the tips are very helpful and cover lesser-known details.

cryptocoding lists 'coding rules' for implementations of cryptographic operations and operations involving secret or sensitive values. It's like the low-level equivalent of the above.