add Guidebook description of rogue level

This is in response to the bug report we got however long ago
about the map display breaking when the [unfamiliar to player]
rogue level was reached.  It probably wouldn't have helped back
then since the subset of players who read the documentation is
about same subset as those who expect the Spanish Inquisition.

I wasn't sure whether appending "'s" to an italicized word
should be italicized itself and made it revert to the regular
font instead.  That should be changed if it's incorrect usage.

doc/Guidebook.mn

@@ -1,4 +1,4 @@
-.\" $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.399 $ $NHDT-Date: 1606324515 2020/11/25 17:15:15 $
+.\" $NHDT-Branch: NetHack-3.7 $:$NHDT-Revision: 1.400 $ $NHDT-Date: 1606328499 2020/11/25 18:21:39 $
 .\"
 .\" This is an excerpt from the 'roff' man page from the 'groff' package.
 .\" Guidebook.mn currently does *not* fully adhere to these guidelines.
@@ -103,7 +103,7 @@ travel, you see the ancient ruins that mark the entrance to the
 Mazes of Menace.  It is late at night, so you make camp at the entrance
 and spend the night sleeping under the open skies.  In the morning, you
 gather your gear, eat what may be your last meal outside, and enter the
-dungeon...
+dungeon....
 .
 .hn 1
 What is going on here?
@@ -1991,6 +1991,23 @@ The
 .op run_mode
 option controls how frequently the map gets redrawn when moving more
 than one step in a single command (so when rushing, running, or traveling).
+.hn 2
+Rogue level
+.pg
+One dungeon level (occurring in mid to late teens of the main dungeon)
+is a tribute to the ancestor game \fIhack\fP's inspiration \fIrogue\fP.
+.pg
+It is usually displayed differently from other levels: possibly in
+characters instead of tiles, or without line-drawing symbols if already
+in characters; also, gold is shown as \f(CR*\fP rather than \f(CR$\fP
+and stairs are shown as \f(CR%\fP rather than \f(CR<\fP and \f(CR>\fP.
+There are some minor differences in actual game play: doorways lack
+doors; a scroll, wand, or spell of light used in a room lights up the
+whole room rather than within a radius around your character.
+And monsters represented by lower-case letters aren't randomly
+generated on the rogue level.
+.pg
+The slight strangeness of this level is a feature, not a bug....
 .
 .hn 1
 Monsters

doc/Guidebook.tex

@@ -2075,7 +2075,7 @@ Shops do not get restocked with new items, regardless of inventory depletion.
 \end{itemize}
 
 %.hn 2
-\subsubsection*{Movement feedback}
+\subsection*{Movement feedback}
 
 %.pg
 Moving around the map usually provides no
@@ -2161,6 +2161,27 @@ The
 option controls how frequently the map gets redrawn when moving more
 than one step in a single command (so when rushing, running, or traveling).
 
+%.hn 2
+\subsection*{Rogue level}
+
+%.pg
+One dungeon level (occurring in mid to late teens of the main dungeon)
+is a tribute to the ancestor game {\it hack}'s inspiration {\it rogue}.
+
+%.pg
+It is usually displayed differently from other levels: possibly in
+characters instead of tiles, or without line-drawing symbols if already
+in characters; also, gold is shown as {\tt *} rather than {\tt \verb+$+}
+and stairs are shown as {\tt \verb+%+} rather than {\tt <} and {\tt >}.
+There are some minor differences in actual game play: doorways lack
+doors; a scroll, wand, or spell of light used in a room lights up the
+whole room rather than within a radius around your character.
+And monsters represented by lower-case letters aren't randomly
+generated on the rogue level.
+
+%.pg
+The slight strangeness of this level is a feature, not a bug....
+
 %.hn 1
 \section{Monsters}
 
@@ -4848,7 +4869,7 @@ if this does not correct the problem, try {\tt !color}.
 Cannot be set with the `{\tt O}' command.
 \elist
 
-%.nh 2
+%.hn 2
 \subsection*{Regular Expressions}
 
 %.pg