Update README.md

Author: Nick-S-2018

README.md

@@ -3,7 +3,7 @@
 Сlient for Manticore Search.
 
 
-❗ WARNING: this is a development version of the client. The latest release's readme is https://github.com/manticoresoftware/manticoresearch-javascript/tree/9.0.0
+❗ WARNING: this is a development version of the client. The latest release's readme is https://github.com/manticoresoftware/manticoresearch-javascript/tree/8.1.0
 
 ## Compatibility Table