Proposal to add Cryptocurrencies category

[kornelski]

Projects related to cryptocurrencies/blockchains are quite distinct, and Rust has some significant users in the world of cryptocurrencies.

There already are more crates related to cryptocurrencies than: authentication, caching, configuration, wasm, http clients, macos apis, cargo plugins, build utilities, value formatting, date and time, internationalization, template engines, audio, video, text editors, emulators, simulators and visualization.

I suggest adding Cryptocurrencies as a subcategory of Cryptography. It could be described as "Libraries and tools for digital currencies, and distributed ledgers."

I've prototyped it by fuzzy matching keywords of existing crates to form a new category:

https://crates.rs/cryptography/cryptocurrencies

[kzys]

@kornelski @carols10cents Resolving? (Why didn't @bors close the issue?)