Fix README

README.md

@@ -126,7 +126,7 @@ Validator                               | Description
 **isIMEI(str [, options]))**                         | check if the string is a valid IMEI number. Imei should be of format `###############` or `##-######-######-#`.<br/><br/>`options` is an object which can contain the keys `allow_hyphens`. Defaults to first format . If allow_hyphens is set to true, the validator will validate the second format.
 **isIn(str, values)**                   | check if the string is in a array of allowed values.
 **isInt(str [, options])**              | check if the string is an integer.<br/><br/>`options` is an object which can contain the keys `min` and/or `max` to check the integer is within boundaries (e.g. `{ min: 10, max: 99 }`). `options` can also contain the key `allow_leading_zeroes`, which when set to false will disallow integer values with leading zeroes (e.g. `{ allow_leading_zeroes: false }`). Finally, `options` can contain the keys `gt` and/or `lt` which will enforce integers being greater than or less than, respectively, the value provided (e.g. `{gt: 1, lt: 4}` for a number between 1 and 4).
-**isIP(str [, version])**               | check if the string is an IP (version 4 or 6).
+**isIP(str [, options])**               | check if the string is an IP address (version 4 or 6).<br/><br/>`options` is an object that defaults to `{ version: '' }`.<br/><br/>**Options:**<br/>`version`: defines which IP version to compare to. Accepted values: `4`, `6`, `'4'`, `'6'`.
 **isIPRange(str [, version])**          | check if the string is an IP Range (version 4 or 6).
 **isISBN(str [, version])**             | check if the string is an ISBN (version 10 or 13).
 **isISIN(str)**                         | check if the string is an [ISIN][ISIN] (stock/security identifier).