xB: fix up the special IPC command's name

To reflect the new disorder.

xB.adoc

@@ -57,24 +57,24 @@ Plugins
 -------
 Plugins communicate with the bot over their standard input and output streams
 using the IRC protocol.  (Caveat: the standard C library doesn't automatically
-flush FILE streams for pipes on newlines.)  A special *ZYKLONB* command is
-introduced for RPC, with the following subcommands:
+flush FILE streams for pipes on newlines.)  A special *XB* command is introduced
+for RPC, with the following subcommands:
 
-*ZYKLONB get_config* _key_::
+*XB get_config* _key_::
 	Request the value of the given configuration option.  If no such option
 	exists, the value will be empty.  The response will be delivered in
 	the following format:
 +
 ```
-ZYKLONB :value
+XB :value
 ```
 +
 This is particularly useful for retrieving the *prefix* string.
 
-*ZYKLONB print* _message_::
+*XB print* _message_::
 	Make the bot print the _message_ on its standard output.
 
-*ZYKLONB register*::
+*XB register*::
 	Once a plugin issues this command, it will start receiving all of the bot's
 	incoming IRC traffic, which includes data from the initialization period.