sound option in Guidebook

E-mail report from <Someone>.  "sound" option wasn't document.  I also
noticed that the SOUND and SOUNDDIR config file entries were incorrectly
named in lower case, and documented as "options", which they aren't.
The Guidebook calls SOUND an entry later on, so call them that earlier as well.

doc/Guidebook.tex

@@ -27,7 +27,7 @@
 \begin{document}
 %
 % input file: guidebook.mn
-% $Revision: 1.54 $ $Date: 2002/09/24 09:42:53 $
+% $Revision: 1.55 $ $Date: 2002/09/26 07:37:12 $
 %
 %.ds h0 "
 %.ds h1 %.ds h2 \%
@@ -2488,6 +2488,10 @@ Suppress terminal beeps (default on).
 \item[\ib{sortpack}]
 Sort the pack contents by type when displaying inventory (default on).
 %.lp
+\item[\ib{sound}]
+Enable messages about what your character hears (default on).
+Note that this has nothing to do with your computer's audio capabilities.
+%.lp
 \item[\ib{standout}]
 Boldface monsters and ``{\tt --More--}'' (default off).
 %.lp
@@ -2750,15 +2754,15 @@ At this time the Qt port and the win32tty and win32gui ports support the
 use of user sounds.
 
 %.pg
-The following config file options are relevant to mapping user sounds
+The following config file entries are relevant to mapping user sounds
 to messages:
 
 \blist{}
 %.lp
-\item[\ib{soundir}]
+\item[\ib{SOUNDDIR}]
 The directory that houses the sound files to be played.
 %.lp
-\item[\ib{sound}]
+\item[\ib{SOUND}]
 An entry that maps a sound file to a user-specified message pattern.
 Each SOUND entry is broken down into the following parts: