feat(isTaxID): Add EU-UK TIN validation

README.md

@@ -150,7 +150,7 @@ Validator                               | Description
 **isSurrogatePair(str)**                | check if the string contains any surrogate pairs chars.
 **isUppercase(str)**                    | check if the string is uppercase.
 **isSlug**                              | Check if the string is of type slug. `Options` allow a single hyphen between string. e.g. [`cn-cn`, `cn-c-c`]
-**isTaxID(str, locale)**                | Check if the given value is a valid Tax Identification    Number. Default locale is `en-US`
+**isTaxID(str, locale)**                | Check if the given value is a valid Tax Identification    Number. Default locale is `en-US`.<br/><br/>More info about exact TIN support can be found in `src/lib/isTaxID.js`<br/><br/>Supported locales: `[ 'bg-BG', 'cs-CZ', 'de-AT', 'de-DE', 'dk-DK', 'el-CY', 'el-GR', 'en-GB', 'en-IE', 'en-US', 'es-ES', 'et-EE', 'fi-FI', 'fr-BE', 'fr-FR', 'fr-LU', 'hr-HR', 'hu-HU', 'it-IT', 'lb-LU', 'lt-LT', 'lv-LV' 'mt-MT', 'nl-BE', 'nl-NL', 'pl-PL', 'pt-PT', 'ro-RO', 'sk-SK', 'sl-SI', 'sv-SE' ]`
 **isURL(str [, options])**              | check if the string is an URL.<br/><br/>`options` is an object which defaults to `{ protocols: ['http','https','ftp'], require_tld: true, require_protocol: false, require_host: true, require_valid_protocol: true, allow_underscores: false, host_whitelist: false, host_blacklist: false, allow_trailing_dot: false, allow_protocol_relative_urls: false, disallow_auth: false }`.<br/><br/>require_protocol - if set as true isURL will return false if protocol is not present in the URL.<br/>require_valid_protocol - isURL will check if the URL's protocol is present in the protocols option.<br/>protocols - valid protocols can be modified with this option.<br/>require_host - if set as false isURL will not check if host is present in the URL.<br/>require_port - if set as true isURL will check if port is present in the URL.<br/>allow_protocol_relative_urls - if set as true protocol relative URLs will be allowed.<br/>validate_length - if set as false isURL will skip string length validation (2083 characters is IE max URL length).
 **isUUID(str [, version])**             | check if the string is a UUID (version 3, 4 or 5).
 **isVariableWidth(str)**                | check if the string contains a mixture of full and half-width chars.