Render example correctly

* Fix rendering of [UNIXSocket.html#recv_io](http://www.ruby-doc.org/stdlib-2.1.0/libdoc/socket/rdoc/UNIXSocket.html#method-i-recv_io)
* Fix sentence

### Rendering before
![screen shot 2014-10-08 at 13 11 24](https://cloud.githubusercontent.com/assets/290596/4558160/5ab90652-4edc-11e4-9ed3-01f01a108165.png)
### After
![screen shot 2014-10-08 at 13 11 41](https://cloud.githubusercontent.com/assets/290596/4558161/5fd1f4f0-4edc-11e4-8d60-3cb43e2a3d8c.png)