Merge pull request #3476 from ipfs/docs/bitswap-proto

update message.proto

exchange/bitswap/message/pb/message.proto

@@ -5,7 +5,7 @@ message Message {
   message Wantlist {
 
     message Entry {
-      optional string block = 1; // the block key
+      optional string block = 1; 	// the block cid (cidV0 in bitswap 1.0.0, cidV1 in bitswap 1.1.0)
       optional int32 priority = 2; 	// the priority (normalized). default to 1
       optional bool cancel = 3;  	// whether this revokes an entry
     }
@@ -15,11 +15,11 @@ message Message {
   }
 
   message Block {
-	optional bytes prefix = 1;
+    optional bytes prefix = 1;		// CID prefix (cid version, multicodec and multihash prefix (type + length)
     optional bytes data = 2;
   }
 
   optional Wantlist wantlist = 1;
-  repeated bytes blocks = 2;
-  repeated Block payload = 3;
+  repeated bytes blocks = 2;		// used to send Blocks in bitswap 1.0.0
+  repeated Block payload = 3;		// used to send Blocks in bitswap 1.1.0
 }