Fix doc errors (missing links, etc).

zebra-chain/src/transaction/joinsplit.rs

@@ -40,7 +40,9 @@ pub struct JoinSplit<P: ZkSnarkProof> {
     ///
     /// XXX refine type to [T; 2] -- there are two macs
     pub vmacs: [[u8; 32]; 2],
-    /// A ZK JoinSplit proof, either a [`Groth16Proof`] or a [`Bctv14Proof`].
+    /// A ZK JoinSplit proof, either a
+    /// [`Groth16Proof`](crate::proofs::Groth16Proof) or a
+    /// [`Bctv14Proof`](crate::proofs::Bctv14Proof).
     pub zkproof: P,
     /// A ciphertext component for this output note.
     ///

zebra-chain/src/transaction/shielded_data.rs

@@ -30,7 +30,7 @@ pub struct SpendDescription {
 
 /// A _Output Description_, as described in [protocol specification §7.4][ps].
 ///
-/// https://zips.z.cash/protocol/protocol.pdf#outputencoding
+/// [ps]: https://zips.z.cash/protocol/protocol.pdf#outputencoding
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct OutputDescription {
     /// A value commitment to the value of the input note.