Add CountryStateCity (#1768)

README.md

@@ -525,6 +525,7 @@ API | Description | Auth | HTTPS | CORS |
 | [Cep.la](http://cep.la/) | Brazil RESTful API to find information about streets, zip codes, neighborhoods, cities and states | No | No | Unknown |
 | [CitySDK](http://www.citysdk.eu/citysdk-toolkit/) | Open APIs for select European cities | No | Yes | Unknown |
 | [Country](http://country.is/) | Get your visitors' country from their IP | No | Yes | Yes |
+| [CountryStateCity](https://countrystatecity.in/) | World countries, states, regions, provinces, cities & towns in JSON, SQL, XML, YAML, & CSV format | `apiKey` | Yes | Yes |
 | [Daum Maps](http://apis.map.daum.net/) | Daum Maps provide multiple APIs for Korean maps | `apiKey` | No | Unknown |
 | [FreeGeoIP](https://freegeoip.app/) | Free geo ip information, no registration required. 15k/hour rate limit | No | Yes | Yes |
 | [GeoApi](https://api.gouv.fr/api/geoapi.html) | French geographical data | No | Yes | Unknown |