docs: fix isLicensePlate description

* locale is actually not optional currently. the function expects a string that is either literally 'any' or one of the supported locales
* format description consistently with the others validators

Author: pano9000

README.md

@@ -140,7 +140,7 @@ Validator                               | Description
 **isJWT(str)**                         | check if the string is valid JWT token.
 **isLatLong(str [, options])**                      | check if the string is a valid latitude-longitude coordinate in the format `lat,long` or `lat, long`.<br/><br/>`options` is an object that defaults to `{ checkDMS: false }`. Pass `checkDMS` as `true` to validate DMS(degrees, minutes, and seconds) latitude-longitude format.
 **isLength(str [, options])**              | check if the string's length falls in a range.<br/><br/>`options` is an object which defaults to `{ min: 0, max: undefined }`. Note: this function takes into account surrogate pairs.
-**isLicensePlate(str [, locale])**     | check if the string matches the format of a country's license plate.<br/><br/>(locale is one of `['cs-CZ', 'de-DE', 'de-LI', 'fi-FI', 'pt-BR', 'pt-PT', 'sq-AL', 'sv-SE', 'en-IN', 'hi-IN', 'gu-IN', 'as-IN', 'bn-IN', 'kn-IN', 'ml-IN', 'mr-IN', 'or-IN', 'pa-IN', 'sa-IN', 'ta-IN', 'te-IN', 'kok-IN']` or `any`)
+**isLicensePlate(str, locale)**     | check if the string matches the format of a country's license plate.<br/><br/>`locale` is one of `['cs-CZ', 'de-DE', 'de-LI', 'fi-FI', 'pt-BR', 'pt-PT', 'sq-AL', 'sv-SE', 'en-IN', 'hi-IN', 'gu-IN', 'as-IN', 'bn-IN', 'kn-IN', 'ml-IN', 'mr-IN', 'or-IN', 'pa-IN', 'sa-IN', 'ta-IN', 'te-IN', 'kok-IN']` or `'any'`.
 **isLocale(str)**                       | check if the string is a locale.
 **isLowercase(str)**                    | check if the string is lowercase.
 **isLuhnValid(str)**                    | check if the string passes the [Luhn check][Luhn Check].