docs($http): document $httpProvider.interceptors in $httpProvider documentation

☆.。.：・゜☆ HASHBANG #NGEUROPE ☆.。.：・゜☆

Fixes #9366
Closes #9728

src/ng/http.js

@@ -144,9 +144,18 @@ function $HttpProvider() {
   };
 
   /**
-   * Are ordered by request, i.e. they are applied in the same order as the
+   * @ngdoc property
+   * @name $httpProvider#interceptors
+   * @description
+   *
+   * Array containing service factories for all synchronous or asynchronous {@link ng.$http $http}
+   * pre-processing of request or postprocessing of responses.
+   *
+   * These service factories are ordered by request, i.e. they are applied in the same order as the
    * array, on request, but reverse order, on response.
-   */
+   *
+   * {@link ng.$http#interceptors Interceptors detailed info}
+   **/
   var interceptorFactories = this.interceptors = [];
 
   /**