Merge bitcoindevkit/bdk#478: Fix typos in comments

7f8103dd76 Fix typos in comments (thunderbiscuit)

Pull request description:

  ### Description

  This PR fixes a bunch of small typos in comments. I'm getting acquainted with the codebase and found a few typos just by chance, and ended up going through it with an IDE searching for typos in all files.

  ### Notes to the reviewers

  To be clear, this PR _only addresses typos that are within comments_.

  ### Checklists

  * [x] I've signed all my commits
  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)
  * [x] I ran `cargo fmt` and `cargo clippy` before committing

ACKs for top commit:
  notmandatory:
    ACK 7f8103dd76

Tree-SHA512: eb3f8f21cbd05de06292affd9ef69c21b52022dfdf25c562c8f4d9c9c011f18175dff0c650cb7efcfb2b665f2af80d9a153be3d12327c47796b0d00bfd5d9803

src/wallet/mod.rs

@@ -721,7 +721,7 @@ where
     /// Bump the fee of a transaction previously created with this wallet.
     ///
     /// Returns an error if the transaction is already confirmed or doesn't explicitly signal
-    /// *repalce by fee* (RBF). If the transaction can be fee bumped then it returns a [`TxBuilder`]
+    /// *replace by fee* (RBF). If the transaction can be fee bumped then it returns a [`TxBuilder`]
     /// pre-populated with the inputs and outputs of the original transaction.
     ///
     /// ## Example
@@ -1059,7 +1059,7 @@ where
         &self.secp
     }
 
-    /// Returns the descriptor used to create adddresses for a particular `keychain`.
+    /// Returns the descriptor used to create addresses for a particular `keychain`.
     pub fn get_descriptor_for_keychain(&self, keychain: KeychainKind) -> &ExtendedDescriptor {
         let (descriptor, _) = self._get_descriptor_for_keychain(keychain);
         descriptor