doc/dlb.6: Revise description

Content:
* Document that the command has a default file list.
* Demote "COMMANDS" section to "Operations" subsection.  The former term
  is (1) too easily confused with Unix commands and (2) not a widely
  used section heading in man pages.

Style:
* Italicize command names.
* Italicize file names.
* Use idiomatic man page cross references.
* Present operation and option letters in alphabetical order.
* Render option descriptions as full sentences.
* Set bug list as a bulleted list.

Markup:
* Break input lines at sentence boundaries.
* Favor use of man(7) font selection and alternation macros over roff(7)
  font selection escape sequences.
* Drop numerous extraneous paragraphing macro calls.  See subsection
  "Horizontal and vertical spacing" of groff_man(7).
* Replace use of *roff requests to break lines and vertically space with
  calls of paragraphing macros, which is what they're for.  Two things
  the page author didn't know: `.sp 1` already implies a break, so the
  preceding `.br` was redundant.  `.sp 1` without an argument already
  means to vertically space by 1 vee; that is, the "1" argument was
  superfluous.  It was a bad idea anyway because the default
  inter-paragraph spacing in man(7) is not one vee, but 0.4v--this
  matters when typesetting.  It has also been the case since 1979.
* Use `RS` and `RE` macros instead of a literal tab to achieve a
  relative inset.  Use of the macros is more idiomatic.
* Use `EX` and `EE` to attempt to set the examples in a monospaced font
  family.  These are extensions and are silently ignored by formatters
  that don't support them.

  groff_man(7):
     .EX
     .EE    Begin and end example.  After .EX, filling is disabled and a
            constant‐width (monospaced) font is selected.  Calling .EE
            enables filling and restores the previous font.

            .EX and .EE are extensions introduced in Ninth Edition Unix.
            Documenter’s Workbench, Heirloom Doctools, and Plan 9
            troffs, and mandoc (since 1.12.2) also support them.
            Solaris troff does not.  See subsection “Use of extensions”
            in groff_man_style(7).
* Kill off useless trailing space on input line.

doc/dlb.6

@@ -51,12 +51,22 @@ dlb \- NetHack data librarian
 \&.\|.\|.
 .SH DESCRIPTION
 .I Dlb
-is a file archiving tool in the spirit (and tradition) of tar for
+is a file archiving tool in the spirit (and tradition) of
-NetHack version 3.1 and higher.  It is used to maintain the
+.IR tar (1)
-archive files from which NetHack reads special level files and other
+for
-read-only information.  Note that like tar the command and option
+.IR nethack (6)
-specifiers are specified as a continuous string and are followed
+version 3.1 and higher.
-by any arguments required in the same order as the option specifiers.
+It is used to maintain the
+archive files from which the game reads special level files and other
+read-only information.
+Note that like
+.IR tar ,
+the letters specifying the operation and options
+are expressed as a continuous string.
+Unlike
+.IR tar ,
+.I dlb
+is configured with a default set of file names to process.
 .ig
 .PP
 ^?ALLDOCS
@@ -72,67 +82,75 @@ configuration.
 ^.
 ^.
 ..
-.SH COMMANDS
+.SS Operations
-The
-.B x
-command causes
-.I dlb
-to extract the contents of the archive into the current directory.
-.PP
-The
 .B c
-command causes
+causes
 .I dlb
 to create a new archive from files in the current directory.
 .PP
-The
 .B t
-command lists the files in the archive.
+lists the files in the archive.
-.SH OPTIONS AND ARGUMENTS
+.PP
-.TP 12m
+.B x
-\fBv
+causes
-verbose output
+.I dlb
-.br
+to extract the contents of the archive into the current directory.
-.sp 1
+.SH OPTIONS
+.TP 13n \" "I list-file" + 2n
+.BI "C " dir
+Change directory to
+.I dir
+before trying to
+read any files.
 .TP
-\fBf\fI\ archive
+.BI "f " archive
-specify the archive.  Default if f not specified is
+Read from or write to
-LIBFILE (usually the nhdat file in the playground).
+.I archive
-.br
+instead of LIBFILE
-.sp 1
+(usually the
+.I nhdat
+file in the playground).
 .TP
-\fBI\fI\ lfile
+.BI "I " list-file
-specify the file containing the list of files to
+Read from
-put in to or extract from the archive if no files are listed
+.I list-file
-on the command line.  Default for archive creation if no files
+the names of files to emplace within or extract from the archive.
-are listed is LIBLISTFILE.
+The default for archive creation is LIBLISTFILE.
-.br
-.sp 1
 .TP
-\fBC\fI\ dir
+.B v
-change directory.  Changes directory before trying to
+Operate verbosely.
-read any files (including the archive and the lfile).
-.br
 .SH EXAMPLES
 Create the default archive from the default file list:
-.br
+.RS
-	dlb c
+.EX
-.sp 1
+dlb c
-List the contents of the archive 'foo':
+.EE
-.br
+.RE
-	dlb tf foo
-.SH AUTHOR
 .PP
+List the contents of the archive
+.IR foo :
+.RS
+.EX
+dlb tf foo
+.EE
+.RE
+.SH AUTHOR
 Kenneth Lorber
 .SH "SEE ALSO"
-.PP
+.IR nethack (6),
-nethack(6), tar(1)
+.IR tar (1)
 .SH BUGS
-.PP
+.IP \(bu 2n
-Not a good tar emulation; - does not mean stdin or stdout.
+Not a good
+.I tar
+emulation;
+.B -
+does not mean stdin or stdout.
+.IP \(bu
 Should include an optional compression facility.
+.IP \(bu
 Not all read-only files for NetHack can be read out of an archive;
-examining the source is the only way to know which files can be. 
+examining the source is the only way to know which files can be.
 .SH COPYRIGHT
 This file is Copyright (C) \*(Na, \*(Nd for version \*(Nb:\*(Nr.
 NetHack may be freely redistributed.  See license for details.