Fixed link to Basho docs

README.markdown

@@ -3,7 +3,7 @@
 This library is a fast Haskell client for the
 [Riak](http://www.basho.com/Riak.html) decentralized key/value data store.
 
-It uses Riak's [protobuf API](http://wiki.basho.com/PBC-API.html) for
+It uses Riak's [protobuf API](http://docs.basho.com/riak/latest/dev/references/protocol-buffers/) for
 optimal performance.
 
 This project was originally the work of Bryan O'Sullivan (<bos@serpentine.com>), and is now being maintained by the engineering team of [Janrain, Inc.](http://janrain.com/).