Add The dog (#2146)

README.md

@@ -124,6 +124,7 @@ API | Description | Auth | HTTPS | CORS |
 | [RandomFox](https://randomfox.ca/floof/) | Random pictures of foxes | No | Yes | No |
 | [RescueGroups](https://userguide.rescuegroups.org/display/APIDG/API+Developers+Guide+Home) | Adoption | No | Yes | Unknown |
 | [Shibe.Online](http://shibe.online/) | Random pictures of Shiba Inu, cats or birds | No | Yes | Yes |
+| [The Dog](https://thedogapi.com/) | A public service all about Dogs, free to use when making your fancy new App, Website or Service | `apiKey` | Yes | Unknown |
 
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 ### Anime