CDRIVER-2287 link to change streams docs

Author: ajdavis

doc/mongoc_change_stream_t.rst

@@ -15,8 +15,7 @@ Synopsis
 :symbol:`mongoc_change_stream_t` is a handle to a change stream. A collection
 change stream can be obtained using :symbol:`mongoc_collection_watch`.
 
-It is recommended to use a :symbol:`mongoc_change_stream_t` and its functions
-instead of a raw aggregation with a ``$changeStream`` stage.
+It is recommended to use a :symbol:`mongoc_change_stream_t` and its functions instead of a raw aggregation with a ``$changeStream`` stage. For more information see the `MongoDB Manual Entry on Change Streams <http://dochub.mongodb.org/core/changestreams>`_.
 
 
 Example
@@ -37,4 +36,4 @@ Example
     mongoc_collection_watch
     mongoc_change_stream_next
     mongoc_change_stream_error_document
-    mongoc_change_stream_destroy
+    mongoc_change_stream_destroy