fix readme comment

Author: YaroslawEkimov

README.md

@@ -15,7 +15,7 @@ This repository contains Aspose.Words Cloud SDK for Ruby source code. This SDK a
 
 ## Enhancements in Version 21.6
 
-- Implemented beta version of CompareDocumentOnline feature with both document sending in request.
+- Implemented beta version of CompareDocumentOnline feature with both document sending in request
 - CompareDocument method now can handle PDF files