Merge rust-bitcoin/rust-bitcoin#2809: doc: fix "lazy line continuations" in markdown

1282b7f34b examples: drop a couple allocations (Andrew Poelstra)
45e0241267 doc: fix "lazy line continuations" in markdown (Andrew Poelstra)

Pull request description:

  Rust nightly as of 2024-05-27 has a new lint which detects list items which are continued by a non-indented line. Markdown treats these as single list items, which they sometimes are, but sometimes we intended them to be on a separate line.

  Also changes the docs for `UntweakedKeypair::tap_tweak` because the existing ones were overly technical and out-of-date.

  Also fixes a minor "no need to create a vec then dereference it" lint in the examples.

ACKs for top commit:
  storopoli:
    ACK 1282b7f34b
  tcharding:
    ACK 1282b7f34b

Tree-SHA512: 989c83b6bbbfbf8ddd2ade63b5f590f76810f4ec56fab432b580a40e3cc1468a0ea657dcc7ad0d4a31d49eb1390219616fec5a76b5680d5fddc3a06d81db30d7

bitcoin/examples/ecdsa-psbt.rs

@@ -232,7 +232,7 @@ impl WatchOnly {
 
         let sigs: Vec<_> = psbt.inputs[0].partial_sigs.values().collect();
         let mut script_witness: Witness = Witness::new();
-        script_witness.push(&sigs[0].to_vec());
+        script_witness.push(sigs[0].serialize());
         script_witness.push(self.input_xpub.to_pub().to_bytes());
 
         psbt.inputs[0].final_script_witness = Some(script_witness);

bitcoin/src/crypto/key.rs

@@ -798,19 +798,16 @@ impl TapTweak for UntweakedKeypair {
     type TweakedAux = TweakedKeypair;
     type TweakedKey = TweakedKeypair;
 
-    /// Tweaks private and public keys within an untweaked [`Keypair`] with corresponding public key
+    /// Applies a Taproot tweak to both keys within the keypair.
-    /// value and optional script tree merkle root.
     ///
-    /// This is done by tweaking private key within the pair using the equation q = p + H(P|c), where
+    /// If `merkle_root` is provided, produces a Taproot key that can be spent by any
-    ///  * q is the tweaked private key
+    /// of the script paths committed to by the root. If it is not provided, produces
-    ///  * p is the internal private key
+    /// a Taproot key which can [provably only be spent via
-    ///  * H is the hash function
+    /// keyspend](https://github.com/bitcoin/bips/blob/master/bip-0341.mediawiki#cite_note-23).
-    ///  * c is the commitment data
-    /// The public key is generated from a private key by multiplying with generator point, Q = qG.
     ///
     /// # Returns
     ///
-    /// The tweaked key and its parity.
+    /// The tweaked keypair.
     fn tap_tweak<C: Verification>(
         self,
         secp: &Secp256k1<C>,

bitcoin/src/merkle_tree/block.rs

@@ -191,6 +191,7 @@ impl Decodable for MerkleBlock {
 ///  - uint256[]  hashes in depth-first order (<= 32*N bytes)
 ///  - varint     number of bytes of flag bits (1-3 bytes)
 ///  - byte[]     flag bits, packed per 8 in a byte, least significant bit first (<= 2*N-1 bits)
+///
 /// The size constraints follow from this.
 #[derive(PartialEq, Eq, Clone, Debug)]
 pub struct PartialMerkleTree {

bitcoin/tests/bip_174.rs

@@ -452,8 +452,8 @@ fn finalize_psbt(mut psbt: Psbt) -> Psbt {
         let sigs: Vec<_> = psbt.inputs[1].partial_sigs.values().collect();
         let mut script_witness = Witness::new();
         script_witness.push([]); // Push 0x00 to the stack.
-        script_witness.push(&sigs[1].to_vec());
+        script_witness.push(sigs[1].serialize());
-        script_witness.push(&sigs[0].to_vec());
+        script_witness.push(sigs[0].serialize());
         script_witness.push(psbt.inputs[1].witness_script.clone().unwrap().as_bytes());
 
         script_witness