Add preferences for existing UI style controls

Some puzzles have keys that make changes to the display style in ways
that would probably have been user preferences if they had existed.
I've added a user preference for each of these.  The keys still work,
and unlike the preferences can be changed without saving any state.

The affected settings are:
 * Labelling colours with numbers in Guess ("L" key)
 * Labelling regions with numbers in Map ("L" key)
 * Whether monsters are shown as letters or pictures in Undead ("A" key)

puzzles.but

@@ -1443,6 +1443,13 @@ that, use one extra colour.
 this increases the search space (making things harder), and is turned on by
 default.
 
+\H{guess-prefs} \I{preferences, for Guess}Guess user preferences
+
+On platforms that support user preferences, the \q{Preferences} option
+on the \q{Game} menu will let you configure whether pegs are labelled
+with their numbers.  Unlike the \q{L} key, this will persist between
+games.
+
 
 \C{pegs} \i{Pegs}
 
@@ -2004,7 +2011,7 @@ Unreasonable puzzles may require guessing and backtracking.
 
 On platforms that support user preferences, the \q{Preferences} option
 on the \q{Game} menu will let you configure the style of the victory
-flash.
+flash and also whether the regions start out labelled with numbers.
 
 
 \C{loopy} \i{Loopy}
@@ -3288,6 +3295,13 @@ These parameters are available from the \q{Custom...} option on the
 
 \dd Controls the difficulty of the generated puzzle.
 
+\H{undead-prefs} \I{preferences, for Undead}Undead user preferences
+
+On platforms that support user preferences, the \q{Preferences} option
+on the \q{Game} menu will let you configure whether Undead uses letters
+or pictures to represent monsters.
+
+
 \C{unruly} \i{Unruly}
 
 \cfg{winhelp-topic}{games.unruly}