Upd Transport for Chicago, US (#2975)

Improve description and change auth from No to apiKey

resolve #2975

README.md

@@ -1623,7 +1623,7 @@ API | Description | Auth | HTTPS | CORS |
 | [Transport for Bordeaux, France](https://opendata.bordeaux-metropole.fr/explore/) | Bordeaux Métropole public transport and more (France) | `apiKey` | Yes | Unknown |
 | [Transport for Boston, US](https://mbta.com/developers/v3-api) | MBTA API | No | No | Unknown |
 | [Transport for Budapest, Hungary](https://bkkfutar.docs.apiary.io) | Budapest public transport API | No | Yes | Unknown |
-| [Transport for Chicago, US](http://www.transitchicago.com/developers/) | CTA | No | No | Unknown |
+| [Transport for Chicago, US](http://www.transitchicago.com/developers/) | Chicago Transit Authority (CTA) | `apiKey` | No | Unknown |
 | [Transport for Czech Republic](https://www.chaps.cz/eng/products/idos-internet) | Czech transport API | No | Yes | Unknown |
 | [Transport for Denver, US](http://www.rtd-denver.com/gtfs-developer-guide.shtml) | RTD | No | No | Unknown |
 | [Transport for Finland](https://digitransit.fi/en/developers/ ) | Finnish transport API | No | Yes | Unknown |