[Feature]: Implement Ed25519 signature

[ggonzalez94]

What is the feature you would like to see?

Reference implementation: https://github.com/RustCrypto/signatures/tree/master/ed25519

Contribution Guidelines

• I agree to follow this project's Contribution Guidelines

[programskillforverification]

I will work on this.

[bidzyyys]

Hey @programskillforverification! Thank you for your interest in contributing to our library 🚀
Go ahead and update us whenever you need any assistance or take a design decision.

[ggonzalez94]

@programskillforverification awesome to have you as a recurring contributor 🚀 - just make sure we prioritize #275 and get that merged ASAP.
Looking forward to seeing your PR on this one!

[programskillforverification]

@ggonzalez94 so we don't use Signature in reference implementation and implement an our own ed25519?

[qalisander]

@programskillforverification correct. I'll gonna add elliptic curves primitives first and based on them add ed25519 curve. After it will be possible to have a signature based on that curve