adjust the guide slightly

roadmap/implementers-guide/src/node/approval/approval-distribution.md

@@ -241,12 +241,12 @@ Imports an approval signature referenced by block hash and candidate index:
 
 #### `unify_with_peer(peer: PeerId, view)`:
 
-1. Initialize a set `fresh_blocks = {}`
+1. Initialize a set `missing_knowledge = {}`
 
 For each block in the view:
   2. Load the `BlockEntry` for the block. If the block is unknown, or the number is less than or equal to the view's finalized number go to step 6.
-  3. Inspect the `known_by` set of the `BlockEntry`. If the peer is already present, go to step 6.
-  4. Add the peer to `known_by` with a cloned version of `block_entry.knowledge`. and add the hash of the block to `fresh_blocks`.
+  3. Inspect the `known_by` set of the `BlockEntry`. If the peer already knows all assignments/approvals, go to step 6.
+  4. Add the peer to `known_by` and add the hash and missing knowledge of the block to `missing_knowledge`.
   5. Return to step 2 with the ancestor of the block.
 
-6. For each block in `fresh_blocks`, send all assignments and approvals for all candidates in those blocks to the peer.
+6. For each block in `missing_knowledge`, send all assignments and approvals for all candidates in those blocks to the peer.