Udpate readme

README.md

@@ -119,7 +119,7 @@ const {
   EMAIL_VENDORS.GMAIL,
   senderHtml,
   senderPlain,
-  senderAttachmentsHashes
+  senderAttachmentsHashes // Only hashes of MIME attachements, no links
 );
 ```
 
@@ -142,7 +142,7 @@ const {
   EMAIL_VENDORS.GMAIL,
   receiverHtml,
   receiverPlain,
-  receiverAttachmentsHashes,
+  receiverAttachmentsHashes, // Only hashes of MIME attachements, no links
   signatures,
   rabinFingerprints
 );