Update README.md

README.md

@@ -422,6 +422,7 @@ API | Description | Auth | HTTPS | CORS |
 | [Battuta](http://battuta.medunes.net) | A (country/region/city) in-cascade location API | `apiKey` | No | Unknown |
 | [Bing Maps](https://www.microsoft.com/maps/) | Create/customize digital maps based on Bing Maps data | `apiKey` | Yes | Unknown |
 | [bng2latlong](https://www.getthedata.com/bng2latlong) | Convert British OSGB36 easting and northing (British National Grid) to WGS84 latitude and longitude | No | Yes | Yes |
+| [Cartes.io](https://github.com/M-Media-Group/Cartes.io/wiki/API) | Create maps and markers for anything | No | Yes | Unknown |
 | [CitySDK](http://www.citysdk.eu/citysdk-toolkit/) | Open APIs for select European cities | No | Yes | Unknown |
 | [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 |