Apply suggestions from code review

Co-authored-by: Alfredo Garcia <[email protected]>

zebra-chain/src/work/difficulty.rs

@@ -294,6 +294,7 @@ impl CompactDifficulty {
     /// Returns a floating-point number representing a difficulty as a multiple
     /// of the minimum difficulty for the provided network.
     // Copied from <https://github.com/zcash/zcash/blob/99ad6fdc3a549ab510422820eea5e5ce9f60a5fd/src/rpc/blockchain.cpp#L34-L74>
+    // TODO: Explain here what this ported code is doing and why, request help to do so with the ECC team.
     pub fn relative_to_network(&self, network: &Network) -> f64 {
         let network_difficulty = network.target_difficulty_limit().to_compact();
 

zebra-rpc/src/methods.rs

@@ -1739,10 +1739,10 @@ impl Default for GetBlock {
 #[derive(Clone, Debug, PartialEq, serde::Serialize)]
 #[serde(untagged)]
 pub enum GetBlockHeader {
-    /// The request block, hex-encoded.
+    /// The request block header, hex-encoded.
     Raw(hex_data::HexData),
 
-    /// The block object.
+    /// The block header object.
     Object(Box<GetBlockHeaderObject>),
 }