opencage: update README

Author: simon04

README.md

@@ -171,11 +171,19 @@ Note that you need an API key to use this service.
 ### Constructor
 
 ```ts
-new L.Control.Geocoder.OpenCage(<String>key);
+new L.Control.Geocoder.OpenCage(<String>key, options);
 // or
-L.Control.Geocoder.opencage(<String>key);
+L.Control.Geocoder.opencage(<String>key, options);
 ```
 
+### Options
+
+| Option                 | Type   | Default                                          | Description                                                                          |
+| ---------------------- | ------ | ------------------------------------------------ | ------------------------------------------------------------------------------------ |
+| `serviceUrl`           | String | `"https://api.opencagedata.com/geocode/v1/json"` | URL of the service                                                                   |
+| `geocodingQueryParams` | Object | `{}`                                             | Additional URL parameters (strings) that will be added to geocoding requests         |
+| `reverseQueryParams`   | Object | `{}`                                             | Additional URL parameters (strings) that will be added to reverse geocoding requests |
+
 ## L.Control.Geocoder.LatLng
 
 Parses basic latitude/longitude strings such as `'50.06773 14.37742'`, `'N50.06773 W14.37742'`, `'S 50° 04.064 E 014° 22.645'`, or `'S 50° 4′ 03.828″, W 14° 22′ 38.712″'`.