Add sodiumoxide unmaintained (#1334)

* Add sodiumoxide unmaintained

* dryoc url

* Add Awesome Rust Cryptography

* Address @tarcieri feedback :thumbsUp:

* Add singatory and ring

* Add Ed25519 libs

crates/sodiumoxide/RUSTSEC-0000-0000.md

@@ -0,0 +1,31 @@
+```toml
+[advisory]
+id = "RUSTSEC-0000-0000"
+package = "sodiumoxide"
+date = "2021-10-22"
+keywords = ["cryptography"]
+informational = "unmaintained"
+url = "https://github.com/sodiumoxide/sodiumoxide/commit/5bb1dfd2578539b89ffb0cbea25f21f00cfb963e"
+
+[versions]
+patched = []
+```
+
+# sodiumoxide is deprecated
+
+Alternatives may be found - not in any specific order:
+
+- [libsodium-sys-stable](https://crates.io/crates/libsodium-sys-stable)
+- [dryoc](https://crates.io/crates/dryoc)
+- [RustCrypto/nacl-compat](https://github.com/RustCrypto/nacl-compat) (`crypto_box`, `crypto_kx`, `crypto_secretstream`)
+- [RustCrypto/xsalsa20poly1305](https://github.com/RustCrypto/AEADs/tree/master/xsalsa20poly1305) (`crypto_secretbox`)
+- [Signatory](https://crates.io/crates/signatory)
+- [ed25519-compact](https://crates.io/crates/ed25519-compact)
+- [ed25519-dalek](https://github.com/dalek-cryptography/ed25519-dalek)
+- [ring](https://github.com/briansmith/ring)
+
+Recommendations can be also found from:
+
+- [Awesome Rust Cryptography](https://github.com/The-DevX-Initiative/RCIG_Coordination_Repo/blob/main/Awesome_Rust_Cryptography.md) 
+
+No direct maintained fork exists.