Update basic IRC operator commands doc for OFTC

Some syntax and available commands on OFTC differ from Freenode,
adjust them were necessary. In particular, setting the channel topic
through ChanServ isn't quite the same any longer.

Change-Id: Id24afc16f7f46476ef761132c9c9a7b491eda47f

doc/source/irc.rst

@@ -281,7 +281,7 @@ Basic Channel Operator Commands
 ===============================
 
 This is not a comprehensive overview of commands available to individuals
-running IRC channels on Freenode, but a basic overview of some of the common
+running IRC channels on OFTC, but a basic overview of some of the common
 commands which may be required for channel operators.
 
 Operator status is sometimes required to perform certain commands in your
@@ -294,17 +294,13 @@ status in a channel, use the following command::
 You don't need to become an operator to change the topic, this can be done
 via Chanserv::
 
-  /msg chanserv topic #channel New topic goes here.
+  /msg chanserv set #channel topic New topic goes here.
 
 If you are curious as to who has access to a channel, you can issue this
 command::
 
   /msg chanserv access #channel list
 
-Visit the `Freenode Channel Guidelines <https://freenode.net/changuide>`_
-for more information about recommended strategies for running channels on
-Freenode.
-
 Banning Disruptive Users
 ========================