Add Code.gov (#959)

* Update README.md

Added Code.gov to the government section of the file

* Update README.md

Fixed `apikey` value to `apiKey` for Code.gov.

README.md

@@ -495,6 +495,7 @@ API | Description | Auth | HTTPS | CORS |
 | [City, Lyon Opendata](https://data.beta.grandlyon.com/fr/accueil) | Lyon(FR) City Open Data | `apiKey` | Yes | Unknown |
 | [City, Nantes Opendata](https://data.nantesmetropole.fr/pages/home/) | Nantes(FR) City Open Data | `apiKey` | Yes | Unknown |
 | [City, Prague Opendata](http://opendata.praha.eu/en) | Prague(CZ) City Open Data | No | No | Unknown |
+| [Code.gov](https://code.gov) | The primary platform for Open Sourse and code sharing for the U.S. Federal Government | `apiKey` | Yes | Unknown |
 | [Colorado Data Engine](http://codataengine.org/) | Formatted and geolocated Colorado public data | No | Yes | Unknown |
 | [Colorado Information Marketplace](https://data.colorado.gov/) | Colorado State Government Open Data | No | Yes | Unknown |
 | [Data USA](https://datausa.io/about/api/) | US Public Data | No | Yes | Unknown |