fix a couple typos in comments in merkle_hasher
Found what I believe to be a couple typos in the comments as I was going through the merkleization code.
@@ -61,7 +61,7 @@ impl HalfNode {
/// zero-value hashes at all depths of the tree.
///
/// This algorithm aims to allocate as little memory as possible and it does this by "folding" up
-/// the tree has each leaf is provided. Consider this step-by-step functional diagram of hashing a
+/// the tree as each leaf is provided. Consider this step-by-step functional diagram of hashing a
/// tree with depth three:
///
/// ## Functional Diagram
@@ -307,7 +307,7 @@ impl MerkleHasher {
/// is a leaf node it will be the value of that leaf).
///
/// This operation will always complete one node, then it will attempt to crawl up the tree and
- /// collapse and other viable nodes. For example, consider a tree of depth 3 (see diagram
+ /// collapse all other completed nodes. For example, consider a tree of depth 3 (see diagram
/// below). When providing the node with id `7`, the node with id `3` will be completed which
/// will also provide the right-node for the `1` node. This function will complete both of
/// those nodes and ultimately find the root of the tree.
