Update base URL for Bing Maps

Microsoft constantly 302's their Maps API which in turn breaks our build. Pointing the reference link to the Maps API documentation should hopefully fix some of these unnecessary failures.

README.md

@@ -271,7 +271,7 @@ Please note a passing build status indicates all listed APIs are available since
 | API | Description | Auth | HTTPS | Link |
 |---|---|---|---|---|
 | adresse.data.gouv.fr | Address database of France. geocoding and reverse. | No | Yes | [Go!](https://adresse.data.gouv.fr) |
-| Bing Maps | Create/customize digital maps based on Bing Maps data | `apiKey` | Yes | [Go!](https://www.microsoft.com/maps/choose-your-bing-maps-API.aspx) |
+| Bing Maps | Create/customize digital maps based on Bing Maps data | `apiKey` | Yes | [Go!](https://www.microsoft.com/maps/) |
 | Geocode.xyz | Provides worldwide forward/reverse geocoding, batch geocoding and geoparsing | No | Yes | [Go!](https://geocode.xyz/) |
 | GeoNames | Place names and other geographical data | No | No | [Go!](http://www.geonames.org/export/web-services.html) |
 | GéoApi | French geographical data | No | Yes | [Go!](https://api.gouv.fr/api/geoapi.html) |