feat(country-code): Search country name

Author: ricardogobbosouza

docs/country-code.md

@@ -9,6 +9,7 @@ validator.countryCode().validate('BR');
 validator.countryCode('alpha-2').validate('BR');
 validator.countryCode('alpha-3').validate('BRA');
 validator.countryCode('numeric').validate('076');
+validator.countryCode('name').validate('Brazil');
 ```
 
 Invalid values:
@@ -18,10 +19,12 @@ validator.countryCode().validate('foo');
 validator.countryCode('alpha-2').validate('076');
 validator.countryCode('alpha-3').validate('BR');
 validator.countryCode('numeric').validate('BRA');
+validator.countryCode('name').validate('foobar');
 ```
 
 You can choose between:
 
 - alpha-2
 - alpha-3
 - numeric
+- name