Update README.md

Signed-off-by: Lewis Marshall <lewis@lmars.net>

README.md

@@ -48,22 +48,23 @@ client = Ably::Realtime.new(key: 'xxxxx')
 client = Ably::Realtime.new(token: 'xxxxx')
 ```
 
-### Connection
-
-Successful connection:
+and that a connection has been established:
 
 ```ruby
 client.connection.connect do
   # successful connection
 end
 ```
 
-Failed connection:
+Connection errors can be handled by registering an errback:
 
 ```ruby
 connection_result = client.connection.connect
+connection_result.callback = Proc.new do
+  # successful connection
+end
 connection_result.errback = Proc.new do
-  # failed connection
+  # handle failed connection
 end
 ```