Add write_deadline configuration option [ci skip]

README.md

@@ -247,6 +247,10 @@ max_control_line: 512
 
 # maximum payload
 max_payload: 65536
+
+# Duration the server can block on a socket write to a client.  Exceeding the 
+# deadline will designate a client as a slow consumer.
+write_deadline: "2s"
 ```
 
 Inside configuration files, string values support the following escape characters: `\xXX, \t, \n, \r, \", \\`.  Take note that when specifying directory paths in options such as `pid_file` and `log_file` on Windows, you'll need to escape backslashes, e.g. `log_file:  "c:\\logging\\log.txt"`, or use unix style (`/`) path separators.