Update README.md

Author: Renat Zubairov

README.md

@@ -49,7 +49,12 @@ VALUES
 ```
 
 Following types are supported:
-
+ * ``string``
+ * ``number``
+ * ``bigint``
+ * ``boolean`` (will be converted to MSSQL ``bit``)
+ * ``date``
+more details can be found [here](https://github.com/elasticio/mssql-component/blob/master/lib/actions/insert.js#L25)
 
 ## Authentication