Add CheetahO (#2635)

README.md

@@ -1184,6 +1184,7 @@ API | Description | Auth | HTTPS | CORS |
 |---|---|---|---|---|
 | [apilayer screenshotlayer](https://screenshotlayer.com) | URL 2 Image | No | Yes | Unknown |
 | [Bruzu](https://docs.bruzu.com) | Image generation with query string | `apiKey` | Yes | Yes |
+| [CheetahO](https://cheetaho.com/docs/getting-started/) | Photo optimization and resize | `apiKey` | Yes | Unknown |
 | [Dagpi](https://dagpi.xyz) | Image manipulation and processing | `apiKey` | Yes | Unknown |
 | [Flickr](https://www.flickr.com/services/api/) | Flickr Services | `OAuth` | Yes | Unknown |
 | [Getty Images](http://developers.gettyimages.com/en/) | Build applications using the world's most powerful imagery | `OAuth` | Yes | Unknown |