Format channel types as code in README

Co-Authored-By: WillSewell <[email protected]>

Author: damdo

README.md

@@ -2,7 +2,7 @@
 
 [![Build Status](https://travis-ci.org/pusher/pusher-http-python.svg?branch=master)](https://travis-ci.org/pusher/pusher-http-python)
 
-This package lets you trigger events to your client and query the state of your channels. When used with a server, you can validate webhooks and authenticate private- or presence-channels.
+This package lets you trigger events to your client and query the state of your channels. When used with a server, you can validate webhooks and authenticate `private-` or `presence-` channels.
 
 In order to use this library, you need to have a free account on <http://pusher.com>. After registering, you will need the application credentials for your app.