Update Open Charge Map entry

- API requires a free API key, CORS supported.

README.md

@@ -977,7 +977,7 @@ API | Description | Auth | HTTPS | CORS |
 | [Izi](http://api-docs.izi.travel/) | Audio guide for travellers | `apiKey` | Yes | Unknown |
 | [Metro Lisboa](http://app.metrolisboa.pt/status/getLinhas.php) | Delays in subway lines | No | No | No |
 | [Navitia](https://api.navitia.io/) | The open API for building cool stuff with transport data | `apiKey` | Yes | Unknown |
-| [Open Charge Map](https://openchargemap.org/site/develop/api) | Global public registry of electric vehicle charging locations | No | Yes | Unknown |
+| [Open Charge Map](https://openchargemap.org/site/develop/api) | Global public registry of electric vehicle charging locations | `apiKey` | Yes | Yes |
 | [REFUGE Restrooms](https://www.refugerestrooms.org/api/docs/#!/restrooms) | Provides safe restroom access for transgender, intersex and gender nonconforming individuals | No | Yes | Unknown |
 | [Schiphol Airport](https://developer.schiphol.nl/) | Schiphol | `apiKey` | Yes | Unknown |
 | [TransitLand](https://transit.land/documentation/datastore/api-endpoints.html) | Transit Aggregation | No | Yes | Unknown |