Expand blind/accessibility section in the Guidebook

doc/Guidebook.tex

@@ -3995,6 +3995,15 @@ gives you the row and column of your review cursor and the PC cursor.
 These co-ordinates are often useful in giving players a better sense of the
 overall location of items on the screen.
 %.pg
+NetHack can also be compiled with support for sending the game messages
+to an external program, such as a text-to-speech synthesizer. If the #version
+extended command shows "external program as a message handler", your NetHack
+has been compiled with the capability. When compiling NetHack from source
+on Linux and other POSIX systems, define {\it MSGHANDLER\/} to enable it. To use
+the capability, set the environment variable {\it NETHACK\_MSGHANDLER\/} to an
+executable, which will be executed with the game message as the program's
+only parameter.
+%.pg
 While it is not difficult for experienced users to edit the {\it defaults.nh\/}
 file to accomplish this, novices may find this task somewhat daunting.
 Included within the symbol file of all official distributions of NetHack 
@@ -4017,10 +4026,24 @@ use by blind players.
 \item[\ib{menustyle:traditional}]
 This will assist in the interface to speech synthesizers.
 %.lp
+\item[\ib{nomenu\verb+_+overlay}]
+Show menus on a cleared screen and aligned to the left edge.
+%.lp
 \item[\ib{number\verb+_+pad}]
 A lot of speech access programs use the number-pad to review the screen.
 If this is the case, disable the number\verb+_+pad option and use the traditional
 Rogue-like commands.
+%.lp
+\item[\ib{autodescribe}]
+Automatically describe the terrain under the cursor when targeting.
+%.lp
+\item[\ib{mention\verb+_+walls}]
+Give feedback messages when walking towards a wall or when travel command
+was interrupted.
+%.lp
+\item[\ib{whatis\verb+_+coord:compass}]
+When targeting with cursor, describe the cursor position with coordinates
+relative to your character.
 \elist
 
 %.hn2