more Guidebook.mn tweaks

The sample map was being rendered in a proportional-width font for
Guidebook.mn -> Guidebook.ps -> Guidebook.pdf so looked awful.  It
is quite hard to believe that no one ever noticed this.  I wasn't
sure how to force tty font, but it is straightforward to pick
constant-width variant of Roman which seems to be 'roff's universal
font.

Prevent ".nethackrc" from being hyphenated and split across lines.
Ditto for other file names in the same section even though they
hadn't been positioned in spots where they got split.  I put same
thing into Guidebook.tex but I don't know whether their embedded
dots will become a problem there.

Loads of unmatched double quotes were confusing Emacs' nroff-mode
(which unlike tex-mode for Guidebook.tex, wasn't being activated
by default for Guidebook.mn).  Supply missing closing quote for a
bunch of things, convert literal '"' to '\(dq' for ones that aren't
intended to have matching close quote.  And change a bunch of
instances of "text" to ``text'' for rendering as quoted strings.
(There are a lot of single-quoted characters 'c' which should
probably be `c' instead, but I haven't touched those.)

There were several '\e' to render the 'escape' character, but that
is something which can be changed at will.  Use '\\' to explicitly
show backslash instead.  Change several ' - ' and '--' to '\(em'
for M-sized dash.  Right now they all have <space>\(em<space> but
the spaces probably shouldn't be there.

Change instances of 'number_pad' to '.op number_pad' to have it
rendered as an option name.

Remove the obsolete sentence which said that "Elbereth" might be
conditionally excluded.  (This change also made in Guidebook.tex.)

Split some wide lines (wide in the source, not after rendering),
although this wasn't done exhaustively.  For the re-split lines,
put each sentence on its own line as suggested by 'roff' man page.

doc/Guidebook.tex

@@ -816,8 +816,7 @@ Engrave a message on the floor.\\
 %.lp ""
 Engraving the word ``{\tt Elbereth}'' will cause most monsters to not attack
 you hand-to-hand (but if you attack, you will rub it out); this is
-often useful to give yourself a breather.  (This feature may be compiled out
-of the game, so your version might not have it.)
+often useful to give yourself a breather.
 %.lp
 \item[\tb{f}]
 Fire one of the objects placed in your quiver (or quiver sack, or that you
@@ -2698,6 +2697,11 @@ for system administrators.
 %.hn 2
 \subsection*{Using a configuration file}
 
+%override the deduced syllable breaks to prevent hyphenation of file names
+\hyphenation{.nethackrc}
+\hyphenation{defaults.nh}
+\hyphenation{nethack.exe}
+\hyphenation{nethackW.exe}
 %.pg
 The default name of the configuration file varies on different
 operating systems. On DOS and Windows, it is ``defaults.nh''