Connection Layer docs

docs/connection.rst

@@ -1,6 +1,16 @@
 Connection Layer API
 ====================
 
+All of the classes reponsible for handling the connection to the Elasticsearch
+cluster. The default subclasses used can be overriden by passing parameters to the
+:class:`~elasticsearch.Elasticsearch` class. All of the arguments to the client
+will be passed on to :class:`~elasticsearch.Transport`,
+:class:`~elasticsearch.ConnectionPool` and :class:`~elasticsearch.Connection`.
+
+For example if you wanted to use your own implementation of the
+:class:`~elasticsearch.ConnectionSelector` class you can just pass in the
+`selector_class` parameter.
+
 .. py:module:: elasticsearch
 
 Transport
@@ -17,6 +27,13 @@ Connection Pool
    :members:
 
 
+Connection Selector
+-------------------
+
+.. autoclass:: ConnectionSelector(opts)
+   :members:
+
+
 Connection
 ----------