Add readme, module layout

Cargo.toml

@@ -4,8 +4,9 @@ version = "0.1.0"
 authors = ["Henry de Valence <hdevalence@hdevalence.ca>"]
 edition = "2018"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
 [dependencies]
 blake2b_simd = "0.5"
 jubjub = { git = "https://github.com/zkcrypto/jubjub", rev = "e83f7d2bd136498a27f9d943fea635d8682bf2c6" }
+
+[features]
+nightly = []

README.md

@@ -0,0 +1,6 @@
+# redjubjub-zebra
+
+A minimal [Redjubjub][redjubjub] implementation for use in [Zebra][zebra].
+
+[redjubjub]: https://zips.z.cash/protocol/protocol.pdf#concretereddsa
+[zebra]: https://github.com/ZcashFoundation/zebra

src/lib.rs

@@ -1,3 +1,14 @@
+#![cfg_attr(feature = "nightly", feature(external_doc))]
+#![cfg_attr(feature = "nightly", doc(include = "../README.md"))]
+
+//! Docs require the `nightly` feature until RFC 1990 lands.
+
+mod public_key;
+mod secret_key;
+mod signature;
+mod error;
+
+
 #[cfg(test)]
 mod tests {
     #[test]