Add link to GeocoderServiceProvider doc

Author: willdurand

index.markdown

@@ -55,7 +55,8 @@ Here are the links to the official and complete documentation pages:
 * [Geocoder documentation]({{ site.url }}Geocoder)
 * [GeocodableBehavior documentation (Propel)]({{ site.url }}GeocodableBehavior)
 * [GeocoderBundle documentation (Symfony2)]({{ site.url }}BazingaGeocoderBundle)
-* [StackGeoIp (Stack Middleware)]({{ site.url }}StackGeoIp)
+* [StackGeoIp documentation (Stack Middleware)]({{ site.url }}StackGeoIp)
+* [GeocoderServiceProvider documentation (Silex)]({{ site.url }}GeocoderServiceProvider)
 
 
 Cookbook