Add references

src/main/java/swiss/qpq/gajumaru/core/crypto/Ed25519.java

@@ -31,6 +31,13 @@ import swiss.qpq.gajumaru.core.tools.CryptoUtils;
 // Uses exquisitely annoying Radix-2^25.5 field arithmetic. Never do this if you can avoid it.
 // Verified against the canonical Erlang ec_utils (see test/README.md for how).
 
+// References:
+// I don't even know where to start with references, but the tink-java library and pretty much
+// everything (and everyone!) referenced on the lib25519 page deserves a mention.
+// 
+// tink-java: https://github.com/tink-crypto/tink-java
+// lib25519: https://lib25519.cr.yp.to/people.html
+
 // TODO: Craig 2026-08-21
 //  I don't like the allocation of Scratch and Ge all over the place.
 //  If someone were to apply this library to a high-throughput system, with many threads